Math Question

[Rayleigh]

  On 9/11/2014 at 1:03 PM, Turboflat4 said:

 

Sorry for the late response, just seeing this thread.

 

Here's a non-algebra way of solving:

 

From second scenario,

 

With A being filled at 4L/min and B at 3L/min, B is only half-filled when A is filled.

 

Now if A were filled at 4L/min and B at 6L/min, they would both be just-filled at exactly the same time. Hence the capacity of B is (6/4) = (3/2) that of A.

 

From first scenario,

 

In the time taken to fill A at 3L/min, if B were also filled at 3L/min, it would be (2/3) full.

 

In the time taken to fill A at 3L/min, if B were also filled at 5L/min (i.e. 5/3 as quickly), it would now be (2/3)*(5/3) = 10/9 full.

 

That's an overfill of 10/9 - 1 = 10/9 - 9/9 = 1/9 of B's capacity.

 

The volume that overflowed is 5L.

 

So 1/9 of B's capacity is 5L, hence B's capacity is 5*9 = 45L.

Hi all, the PSLE has ended and i thank all bros in MCF for all the help rendered in the solving the math problems. Very much appreciated.

[Loki]

  On 10/1/2014 at 1:08 AM, Rayleigh said:

Hi all, the PSLE has ended and i thank all bros in MCF for all the help rendered in the solving the math problems. Very much appreciated.

 

Yup, my thanks too! I asked a couple. My kid is sooo happy that she will have a 3-month break.

[Mcf777]

my turn next year (P6) to ask more questions......

 

Appreciate all bros who helps with the answers.

 

Thumbs UP!

[Tohto]

Any Math expert can help solve below question..

Thanks.

 

 

Find the last digit of 7²⁰³ X 8¹⁰⁰⁴

Edited March 13, 2015 by Tohto

[Tohto]

  On 3/13/2015 at 6:18 AM, Tohto said:

Any Math expert can help solve below question..

Thanks.

 

 

Find the last digit of 7²⁰³ X 8¹⁰⁰⁴

 

Calling Turboflat4, where are you?

Need your help on the math question....

[Porker]

  On 3/13/2015 at 6:18 AM, Tohto said:

Any Math expert can help solve below question..

Thanks.

 

 

Find the last digit of 7²⁰³ X 8¹⁰⁰⁴

Last digit for 7^{0 is 1}

^{.... 71 is 7}

^{.... 72 is 9}

^{.... 73 is 3}

^{.... 74 is 1}

^{.... 75 is 7}

^{.... 76 is 9}

^{.... 77 is 3}

^{.... 78 is 1}

^{.... 79 is 7}

^{.... 710 is 9}

 

 

^{And so on. So the last digit of 7203 is 3}

 

^{Use the sane method for 81004 to find the last digit. Then multiply both last digits and you will get your answer.}

[Vhtfhwlego]

Question:

On 15 February 2007 (Budget Day), Second Finance Minister Tharman Shanmugaratnam announced that the GST rate would be increased to 7% with effect from 1 July 2007.

The rate increase was accompanied by an offset package to help Singaporeans with the increase in GST, and which would cost the government $4 billion over five years.^[7]

 

 

 

Have it helped Singaporean so far?

 

 

[Carrunner]

  On 3/13/2015 at 9:14 AM, Porker said:

Last digit for 7^{0 is 1}

^{.... 71 is 7}

^{.... 72 is 9}

^{.... 73 is 3}

^{.... 74 is 1}

^{.... 75 is 7}

^{.... 76 is 9}

^{.... 77 is 3}

^{.... 78 is 1}

^{.... 79 is 7}

^{.... 710 is 9}

 

 

^{And so on. So the last digit of 7203 is 3}

 

^{Use the sane method for 81004 to find the last digit. Then multiply both last digits and you will get your answer.}

 

^{wow..... nice..}

  On 3/13/2015 at 9:25 AM, Vhtfhwlego said:

^Question:

^{On 15 February 2007 (Budget Day), Second Finance Minister Tharman Shanmugaratnam announced that the GST rate would be increased to 7% with effect from 1 July 2007.}

^{The rate increase was accompanied by an offset package to help Singaporeans with the increase in GST, and which would cost the government $4 billion over five years.[7]}

 

 

 

^{Have it helped Singaporean so far?}

 

 

 

 

^{Raise GST to help the poor loh. :( elite logic}

[Vid]

  On 3/13/2015 at 9:14 AM, Porker said:

Last digit for 7^{0 is 1}

^{.... 71 is 7}

^{.... 72 is 9}

^{.... 73 is 3}

^{.... 74 is 1}

^{.... 75 is 7}

^{.... 76 is 9}

^{.... 77 is 3}

^{.... 78 is 1}

^{.... 79 is 7}

^{.... 710 is 9}

 

 

^{And so on. So the last digit of 7203 is 3}

 

^{Use the sane method for 81004 to find the last digit. Then multiply both last digits and you will get your answer.}

 

^{You are good when you are sane :D}

[Darryn]

  On 3/13/2015 at 6:18 AM, Tohto said:

Any Math expert can help solve below question..

Thanks.

 

 

Find the last digit of 7²⁰³ X 8¹⁰⁰⁴

I'm gonna guess that it will be the same as the last digit of 7^3 x 8^4

 

But I can't remember the properties of exponents - which is what this is testing...

 

If you know the properties of exponents just apply...will be intuitive

[Tohto]

  On 3/13/2015 at 9:14 AM, Porker said:

Last digit for 7^{0 is 1}

^{.... 71 is 7}

^{.... 72 is 9}

^{.... 73 is 3}

^{.... 74 is 1}

^{.... 75 is 7}

^{.... 76 is 9}

^{.... 77 is 3}

^{.... 78 is 1}

^{.... 79 is 7}

^{.... 710 is 9}

 

 

^{And so on. So the last digit of 7203 is 3}

 

^{Use the sane method for 81004 to find the last digit. Then multiply both last digits and you will get your answer.}

^Thanks.

^{Later let my daughter see wether she understand...}

[Porker]

  On 3/13/2015 at 10:26 AM, Vid said:

 

You are good when you are sane :D

 

I am excellent when I am insane muayhahaha

[Vid]

  On 3/13/2015 at 1:16 PM, Porker said:

 

I am excellent when I am insane muayhahaha

 

Without a doubt

 

[Ender]

  On 10/1/2014 at 1:30 AM, Mcf777 said:

my turn next year (P6) to ask more questions......

 

Appreciate all bros who helps with the answers.

 

Thumbs UP!

Recommend u to go to kiasuparents forum there to post ur questions. My son is doing P6 this year. I use the questions and solutions there to train my son.

[Voodooman]

Amazing brain power, especially mental calculation (start from around 1.07).

 

http://youtu.be/lud-XMSt7-c

 

http://www.japantimes.co.jp/news/2015/03/19/national/china-in-shock-after-japanese-girl-wins-brain-battle/#.VRFmbBjXerX

 

NATIONAL

China in shock after Japanese girl wins brain battle

BY BEN DOOLEY

KYODO

MAR 19, 2015

ARTICLE HISTORY

PRINT SHARE

BEIJING Chinas loss to Japan on a popular game show devoted to mental athletics has left the countrys netizens atwitter and provoked some national soul-searching.

 

The battleground was the popular television show Super Brain, and the eventual winner a 9-year-old Japanese girl.

 

The series is a sort of weekly mental Olympics, pitting teams from around the world against China in a series of three brain-bending events.

 

In recent competitions, China has gone up against Germany and Britain, with contestants fighting over such questions of national honor as who can solve a Rubiks cube the fastest.

 

Last Fridays match against Japan the country China loves to hate was one of the most hotly anticipated, and widely watched, of the season.

 

For the last event in the triathlon, contestants were given mere seconds to find the answers to arithmetic problems that would take the average adult minutes and a calculator to solve.

 

When the dust settled, Japanese math prodigy Rinne Tsujikubo had demolished her Chinese competition, as well as fellow teammate Takeo Sasano.

 

Sasano, who is in his 30s, holds the Guinness World Record for mental addition: 15 three-digit numbers in 1.7 seconds.

 

The diminutive Tsujikubo played it cool throughout the contest, even after she mistakenly wrote one digit in a difficult problem.

 

That error allowed Team China to stay neck-and-neck for most of the competition, but in the last few minutes Tsujikubo completely blew the opposition away.

 

In the final round she multiplied two seven-digit numbers and double-checked her work before her competitors, or teammate, had seemingly even finished writing their answers.

 

The blistering speed with which she solved the problem left everyone, including the audience, dumbfounded and handed a win to Japan.

 

Xinhua, Chinas official news agency, devoted a five-page write-up to the match, lavishing most of its attention on Tsujikubos mind-bending mathleticism.

 

Whats her secret? Studying the Japanese abacus, known as soroban, she told an interviewer before the show.

 

Abacus classes are a common, if not necessarily popular, after-school activity in Japan. After years of practice, devotees develop the ability to do sums on a mental calculator, solely based on visualization.

 

The skill is known as flash anzan (mental calculation) and is the centerpiece of an annual abacus competition.

 

Tsujikubos demonstration of the skill seems to have captivated Chinese viewers, who have watched the online version of the show almost 22 million times. Most were blown away by Tsujikubos superhuman arithmetic skills.

 

But inevitably, online comments showed signs of wounded nationalism. Lets fiercely trample Japan underfoot, one commenter wrote.

 

Other viewers, however, had a more introspective take on Japans victory. Soroban, noted another commenter, were imported to Japan from China, where the tradition has largely died out.

 

The island nation, he wrote, referring to Japan, defeated us with one of the best things left to us by our ancestors. Perhaps, he said, thats worth reflecting on.

[Rayleigh]

Hi MCF Bro, need your help with this math working. While i am able to get the answer, i cant explain it to a P5 boy.

 

A box contain the same number of ten-cent coins and fifty-cent coins. A boy took 20 ten-cent coins and changed into fifty-cent coins of the same value and put them back into the box. Hence the ratio of the number of fifty-cent : ten-cent is 17:5. How much money was in the box.

 

Answer: While I know there are 30 ten-cent coins and 30 fifty-cent coins, i have difficulty in presenting the solution to a P5 level,

Edited April 27, 2015 by Rayleigh

[Jp66]

  On 4/27/2015 at 3:07 PM, Rayleigh said:

Hi MCF Bro, need your help with this math working. While i am able to get the answer, i cant explain it to a P5 boy.

 

A box contain the same number of ten-cent coins and fifty-cent coins. A boy took 20 ten-cent coins and changed into fifty-cent coins of the same value and put them back into the box. Hence the ratio of the number of fifty-cent : ten-cent is 17:5. How much money was in the box.

 

Answer: While I know there are 30 ten-cent coins and 30 fifty-cent coins, i have difficulty in presenting the solution to a P5 level,

 

Bro, hope this helps.

[Porker]

  On 4/27/2015 at 3:07 PM, Rayleigh said:

Hi MCF Bro, need your help with this math working. While i am able to get the answer, i cant explain it to a P5 boy.

 

A box contain the same number of ten-cent coins and fifty-cent coins. A boy took 20 ten-cent coins and changed into fifty-cent coins of the same value and put them back into the box. Hence the ratio of the number of fifty-cent : ten-cent is 17:5. How much money was in the box.

 

Answer: While I know there are 30 ten-cent coins and 30 fifty-cent coins, i have difficulty in presenting the solution to a P5 level,

The syllabus here is ridiculous. Mathematics should always be solved in the shortest and most elegant method as are Physics and other Sciences.