Jake can wash a car in 45 minutes, while Harold can wash the same car in 50 minutes. How long will it take them to wash the car if they work together?
A) $\frac { 19 } { 450 }$ minutes
B) $\frac { 450 } { 19 }$ minutes
C) 40 minutes
D) 45 minutes
E) 5 minutes

Question

Jake can wash a car in 45 minutes, while Harold can wash the same car in 50 minutes. How long will it take them to wash the car if they work together? 
A) $\frac { 19 } { 450 }$ minutes
B) $\frac { 450 } { 19 }$ minutes
C) 40 minutes
D) 45 minutes
E) 5 minutes

Quizplus · Accepted Answer

Let's first find their individual rates of washing the car. 
Jake's rate = 1/45 
Harold's rate = 1/50

When they work together, their rates add up: 
Rate when working together = 1/45 + 1/50 = 19/450

Now we can use the formula: 
Time = Work/Rate

We want to find the time it takes for them to wash one car, so we can let work = 1. 
Time = 1/(19/450) = 450/19

Therefore, the answer is B, 450/19 minutes.

Jake Can Wash a Car in 45 Minutes, While Harold 19450\frac { 19 } { 450 }45019​

Jake Can Wash a Car in 45 Minutes, While Harold $\frac { 19 } { 450 }$