A certain store sells only jacks and marbles. A single jack costs...

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members
swerve wrote:
Sat Jan 18, 2020 2:36 pm
A certain store sells only jacks and marbles. A single jack costs 19 cents and a single marble costs 25 cents. In how many different ways can one spend exactly $10 buying items at this store?

A. 0
B. 1
C. 2
D. 3
E. 4

The OA is D

Source: Veritas Prep
Say one bought x jacks and y marbles, where x and y are nonnegative integers.

Thus, 19x + 25y = 1,000

=> x = (1,000 – 25y)/19 = 25*[(40 – y)/19];

Since x is a non-negative integer, (40 – y)/19 must be a non-negative integer, too.

Possible values of y are 40, 21 and 2; thus the corresponding values of x are 0, 25 and 50. There are three ways.

The correct answer: D

Hope this helps!

-Jay
_________________
Manhattan Review

Locations: Manhattan Review Dilsukhnagar | GMAT Prep Begumpet | GRE Prep Visakhapatnam | Warangal GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.