s27,q16

Suyog · Posted: Thu Sep 27, 2007 3:51 pm Post subject: s27,q16

John 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 ?

(A) 4y (B) 5y (C) 6y
(D) 8y (E) 9y

Nisha1218 · Posted: Thu Sep 27, 2007 4:07 pm Post subject:

I think the answer is B.

- Pick a number of X --> x= 40, john and mary got 40 each in advance
- Calculate hourly rate -->
john works 10 hrs, so hrly rate is 40/10 = $4 hr
mary works 8 hrs (i.e. 2 hrs less than John), so hrly rate is 40/8 = $5 hr
- Mary has to give John $10 (y) in order for him to receive the same hrly rate ((40 advance +10 additional)/10hrs)), thus john's advance payment would be $50
- substitute (y) into the answer choices until you get 50

b - 5(y) = 5(10) = 50

kajcha · Posted: Thu Sep 27, 2007 6:10 pm Post subject:

IMO Ans is E

Both were paid x dollars. Total = 2x

Suppose the hourly rate for both of them = $z/hour

At this rate John should get 10z dollars. Mary should get 8z dollars.

10z+8z = 2x => x = 9z ------(1)

Mary pays "y" dollars from her advance so now she has x-y dollars with her. means x-y = 8z => z = (x-y)/8 -----(2)

replace z in (1) from (2)

x = 9(x-y)/8 => x = 9y. Amount John was paid in advance.

Suyog · Posted: Fri Sep 28, 2007 6:04 am Post subject:

ans E.
Thanks Kajcha!!!

manasi_sh · Posted: Fri Sep 28, 2007 9:04 pm Post subject:

HEY I DINT UNDERSTAND HOW CAN x-y = 8z..please explain again..

ratindasgupta · Posted: Sat Sep 29, 2007 12:44 am Post subject: Re: s27,q16

kajcha · Posted: Sat Sep 29, 2007 5:06 am Post subject:

At z dollars/hour rate Mary should have got 8z dollars.

She was paid x dollars in advance. She is paying J "y" dollars to make it equivalent to z dollars/hour rate. i.e. she was paid more than what she deserved at this rate.

x-y = 8z. Hope this clears the doubt.