word problem

[tanyatomar]

in may mrs Lee's earnings were 60% of mrs lee entire family income. in june mrs lee earned 20% more than in may. if the rest of the family's income was the same both the months, then in june , mrs lee's earnings were aproximately what percent of the lee family total income.

1. 64%
2. 68%
3. 72%
4. 76%
5. 80%

OA: 64%...
on gmat prep i guessed this one as 72%... please do explain how to solve this one...


Thanks ,
Tanya

[vijay.gmat2011]

Say the original total family income was 100 (i.e in May)

Lee salary then would be 60

Now Lee's salary was increased by 20% => New salary is 60 + 12 = 72

New Family total is 100 + 12 = 112

So Lee's salary is 72/112 * 100 = 64%

Hope this helps!

[RonPurewal]

Say the original total family income was 100 (i.e in May)

Lee salary then would be 60

Now Lee's salary was increased by 20% => New salary is 60 + 12 = 72

New Family total is 100 + 12 = 112

So Lee's salary is 72/112 * 100 = 64%

Hope this helps!

that works.

[parakh.rahul]

Say the original total family income was 100 (i.e in May)

Lee salary then would be 60

Now Lee's salary was increased by 20% => New salary is 60 + 12 = 72

New Family total is 100 + 12 = 112

So Lee's salary is 72/112 * 100 = 64%

Hope this helps!

that works.

Well this helps a lot, but it would help further if you could explain us how solve 72/112 * 100 part of the solution faster. I would like to learn how the process of estimation works on this.

Thanks,
Rahul

[RonPurewal]

Well this helps a lot, but it would help further if you could explain us how solve 72/112 * 100 part of the solution faster. I would like to learn how the process of estimation works on this.

Thanks,
Rahul

there's no canonical process; just pick numbers that are close to these ones. for instance, you could use 70/110.

also, it really shouldn't take that long just to do out the long division (7200 divided by 112). if that takes you a ridiculously long time, then you should practice long division and get faster at it.