Need Help in Primary 6 Maths Qns

[Ivan96935sg]

I need some help on the following Maths Qns which I have trouble explaining to my kid. Anyone kind enough to guide me with the explanation?

 

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

[XEvolutioNX]

$36=9/10

$40 =10/10

$40+$16= $56 the amount ken have

devi have $24

if devi give $20 to ken he will have $4 = 1/10

[Ivan96935sg]

$36=9/10

$40 =10/10

$40+$16= $56 the amount ken have

devi have $24

if devi give $20 to ken he will have $4 = 1/10

 

I am sorry to say that I still could not understand the rationale. Perhaps you can further breakup the workings in simpler form? I am terribly sorry.

[Ericongy]

the ans i have is ken 60, devi 28...

[Ivan96935sg]

the ans i have is ken 60, devi 28...

 

May I check with you which method did you use to solve this?

[Ericongy]

May I check with you which method did you use to solve this?

 

simultaneous equation

 

1) K-16=D+16

2) K+20 = 10x(D-20)

 

solve the equation lor...

long time din do math liao.... duno correct onot

[Xdeatel]

Using algebra method,

 

Let X be the amount of money Ken has.

Let Y be the amount of money Devi has.

 

"Ken gives Devi $16, he will have the same amount of money as Devi"

 

X-16 = Y+16

 

"If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's"

 

1/10 (X+20) = Y-20

 

So the two equations are :

 

X-16 = Y+16

 

and

 

1/10 (X+20) = Y-20.

 

Let X = Y,

 

X-16 = Y+16

X = Y + 32 --------(1)

 

1/10 (X+20) = Y-20

X+20 = 10Y-200

X = 10Y-220 -------(2)

 

Sub Equation (1) into (2) :

 

Y+32 = 10Y-220

9Y = 252

Y = 28 ---------(3)

 

Sub Equation (3) into (1):

 

X = 28+32

= 60

 

Therefore Ken and Devi have $60 and $26 each respectively.

Edited March 11, 2010 by Xdeatel

[XEvolutioNX]

but ur 60-16=44 and 26+16=42 not equal

 

[XEvolutioNX]

by the way i think mine is the correct one....... i use the box box thing to slove can't show it here so sorry

[Unfair]

If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

K-16 = D + 16

K = D + 32 -------(1)

 

10 (D-20 ) = K + 20

k = 10D - 220 -----(2)

 

10D-220 = D+32 -------Combine 1&2

9D = 252

D = 28 -------(3)

 

K = 28+32 = 60 -------(4)

[Kermitty]

His working states Devi has $28 but his final answer put $26.

[Dj_spike]

Ken = 40, Devi = 24

Edited March 11, 2010 by Dj_spike

[Babyt]

i dunno how to do liao. so sad...somemore i have a degree...

[Ivan96935sg]

Me too........maths problems really must do more to improve the brain.

[Cerano]

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

Ken -----> x+16

Devi ----> x

 

x-20 = 0.1(x+16)

 

solve for x

then + 16.

[Little_prince]

limbei got masters also take me 10 mins to solve. hahaha....

 

K=60.

D= 28

 

solve simultaneous eqn

 

k-16=D+16 ----(1)

 

D-20 = (k+20)/10 ---- (2)

 

 

Edited March 11, 2010 by Little_prince

[Geboz]

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

Ken -----> x+16

Devi ----> x

 

x-20 = 0.1(x+16)

 

solve for x

then + 16.

 

 

Cannot lah, P6 haven't learn this yet. Must use the model method. But i don't know how.

[Little_prince]

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

Ken -----> x+16

Devi ----> x

 

x-20 = 0.1(x+16)

 

solve for x

then + 16.

 

your answer wrong leh....