GMAT Prep 1 #3_PS Ratio #31

[kwah]

I am having issues figuring this out...

Please advise what the steps are to solve the question attached.

Answer: C

Thank you,
K

[Anurag@Gurome]

I am having issues figuring this out...

Please advise what the steps are to solve the question attached.

Answer: C

Thank you,
K

Let us assume that Kaye and Alberto now have 7x and 5x stamps respectively. Hence, now Kaye has 2x more stamps than Alberto.

Now, before Kaye gave Alberto 10 stamps, Kaye had (7x + 10) stamps and Alberto had (5x - 10).

So, (7x + 10)/(5x - 10) = 5/3
(21x + 30) = (25x - 50)
4x = 80
2x = 40

The correct answer is C.

[kwah]

Can you please explain why we would not start with the equation below?

Since the initial ratio of stamps Kaye and Alberto had were 5x : 3x then...

5x - 10 / 3x + 10 = 7 / 5

This equation shows that Kaye is giving up 10 stamps and Alberto is receiving 10 stamps and thus, the ratio is equal to 7 : 5. This is how I approached the question and got stuck.

If you can please clarify this, it would be greatly appreciated.

K

[dhiren8182]

Hi,
I solved in a way mentioned underneath.
No fo stamps be x.So as per given information it's in ratio k/a= 5x/3x.
Now,as per que stem;
5x-10/3x+10=7/5
solving this we get x=30.
Now putting values in the above equation:5x-10/3x+10=7/5
we get kaye's no of stamps to be 140 and alberto's as 100
so to get how much more stamps kaye has=140-100
so its 40
ANS is c

[dhiren8182]

Hi,
I solved in a way mentioned underneath.
No fo stamps be x.So as per given information it's in ratio k/a= 5x/3x.
Now,as per que stem;
5x-10/3x+10=7/5
solving this we get x=30.
Now putting values in the above equation:5x-10/3x+10=7/5
we get kaye's no of stamps to be 140 and alberto's as 100
so to get how much more stamps kaye has=140-100
so its 40
ANS is c