If Jim earns x dollars per hour

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 75
Joined: Tue Feb 10, 2009 11:30 pm

If Jim earns x dollars per hour

by nhai2003 » Fri Jul 10, 2009 10:57 pm
If Jim earns x dollars per hour, it will take him 4 hours to earn exactly enough money to purchase a particular jacket. If Tom earns y dollars per hour, it will take him exactly 5 hours to earn enough money to purchase the same jacket. How much does the jacket cost?
(1) Tom makes 20% less per hour than Jim does.
(2) x + y = $43.75

:?:

Legendary Member
Posts: 1035
Joined: Wed Aug 27, 2008 10:56 pm
Thanked: 104 times
Followed by:1 members

by scoobydooby » Fri Jul 10, 2009 11:18 pm
would go for B

Jims 4 hrs earnings= cost of jacket=Toms 5 hrs earnings
=> 4x=5y=C (x=jims hourly rate, y= toms hourly rate).......a

1) Tom makes 20% less per hour than Jim does
=>y=0.8x

putting it in..a above, we get 5y=4x
cant work out C from this. not sufficient

2) x + y = $43.75
=> putting x=5/4y (from a) , we can solve for y and hence the cost.
sufficient

Senior | Next Rank: 100 Posts
Posts: 30
Joined: Sat Aug 11, 2007 10:50 am
Thanked: 1 times
GMAT Score:700

by montz » Fri Jul 10, 2009 11:19 pm
Answer B

From the problem statement:

Jim requires 4x dollars (he earns x dollars per hour and needs to work 4 hours to earn enough money) to purchase the jacket.

Similarly Tom requires 5y dollars to pay for the same jacket

we can write that 4x = 5y

Statement A says that y = 80% of x => y = (4/5)x.
This is same as the equation we have already formed from the problem statement. Not sufficient to find the cost.

With Statement B, we have two equations and two variables, which we can solve for either x or y and find the cost of the jacket.

B alone is sufficient