you can try to solve this problem in this manner

John worked for 10 hours
Mary worked for 10-2=8 hours

So total hour of works = 10 + 8 = 18 hours

Let us say in 18 hours total amount of work done = 18 * x unit of work = 18 X unit of work.

Payment for one unit of work= P

John initial Payment = 9XP
Mary initial Payment = 9XP

But John should have been Paid 10XP and Mary should have been paid 8XP.

10XP = 9XP + Y
or
8XP = 9XP - Y

Y= XP

John initial payment = 9XP = 9Y

If anything is not clear, do bug me

heshamelaziry wrote:Johan and Mary were each paid x dollars in advance to do a certain job together. john worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave john y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that john was paid in advance ?

4y

5y

6y

8y

9y


I am lost. I could only write (x/8)-y = x/10 which is wrong.

OA
9y

The key point to solve is 'they have same hourly wage after Mary shares Y dollars.

Hence

(x+y)/10 = (x-y)/8

Solving we get 18y = 2x, which is E

amnt paid to jhn for 10 hrs=x
amnt paid to marry for 8 hrs=x

mary gave jhon $y to equate the horly wage

so new recived amnt is jhn=x+y; hourly wage=(x+y)/10
mary=x-y;hourly wage=(x-y)/8
eqn
(x+y)/10=(x-y)/8
solving x=9y

problem in your approach is that you are reducing y from hourly wage, we need to reduce it from total wage and then equate new hourly wage.

i wasted 4 papers to solve this ,i hate myself

xcusemeplz2009 wrote:amnt paid to jhn for 10 hrs=x
amnt paid to marry for 8 hrs=x

mary gave jhon $y to equate the horly wage

so new recived amnt is jhn=x+y; hourly wage=(x+y)/10
mary=x-y;hourly wage=(x-y)/8
eqn
(x+y)/10=(x-y)/8
solving x=9y

problem in your approach is that you are reducing y from hourly wage, we need to reduce it from total wage and then equate new hourly wage.

i wasted 4 papers to solve this ,i hate myself

I hate myself more for not reaching your way of solving; i saw this same equation many times and makes perfect sense to add y to one side and subtract y form the other !
I am amazed that the people who put this question did not write this answer, instead they made two equations with 3 variables, which made the explanation complicated. They are said to be the best !!!

I have a test in four days and with my performance it doesn't look good.

I have a test in four days and with my performance it doesn't look good.

At this point, your best asset is to be cool & most importantly have ton of confidence. Dont think too much if you were not able to solve few probs. Just learn and keep moving.

heshamelaziry wrote:

xcusemeplz2009 wrote:amnt paid to jhn for 10 hrs=x
amnt paid to marry for 8 hrs=x

mary gave jhon $y to equate the horly wage

so new recived amnt is jhn=x+y; hourly wage=(x+y)/10
mary=x-y;hourly wage=(x-y)/8
eqn
(x+y)/10=(x-y)/8
solving x=9y

problem in your approach is that you are reducing y from hourly wage, we need to reduce it from total wage and then equate new hourly wage.

i wasted 4 papers to solve this ,i hate myself

I hate myself more for not reaching your way of solving; i saw this same equation many times and makes perfect sense to add y to one side and subtract y form the other !
I am amazed that the people who put this question did not write this answer, instead they made two equations with 3 variables, which made the explanation complicated. They are said to be the best !!!

I have a test in four days and with my performance it doesn't look good.

the need for the hour is to be cool and focused ; i ahve seen that GMAT loves to complicate a very very simple problem by twisting the language; but one thing is there for every problem there is a layman method of sol; although its time consuming but some times for an essay type q in maths it helps a lot in solving the problem.......for every q i think a thought process of 10-20 sec is good way to handle it

All the Best