GMAT Question of the Day – Problem Solving – Work/Rate
Worker A and Worker B working together can paint 31 walls per day. If Worker B increases his rate by 1/3 the two of them could paint 34 walls per day. How many walls can Worker A paint in a day?
A. 9
B. 15
C. 19
D. 20
E. 22
[spoiler]E.[/spoiler]
GMAT Question of the Day Solution
This work question may seem a slight bit out of the ordinary but you can tackle it the same way as you would tackle any other work/rate question. Make T’s to organize the information and then work your way towards what you are solving for. In this case we are looking for the rate of Worker A. We are given some information about the two people working together and some information about Worker B. Most likely we’ll be subtracting the rate of Worker B from the combined rate to get the Rate of Worker A. In this question you’re not directly given the rate of Worker B but you’re really only one step removed from figuring that out.
If you are still a little confused about how we figured out that the rate of Worker B is equal to 9 you might consider setting up some parallel equations. Then you can subtract out the rate of Worker A and solve for the rate of Worker B. Here’s an Official GMAT cooperative distance, work, and rate question to practice on: Pumps A, B, and C operate at their respective constant rates…
Here are another bunch of cooperative work and rate questions to practice on:
Here’s a cooperative rate question from the GMAT Official Guide. It’s has the same components mixed up in a slightly different way: Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours
These are all from GMAT Question of the day:
For more distance, work, and rate examples you can also check out our GMAT Question of the Day page
GMAT Question of the Day Signup
Sign up for 1 challenging GMAT question sent to you each week.