john can finish a job in 5 hours. steve can finish the same job in 4 hours. after working together for 2 hour, steve leaves. how long will it take john

Question

Algerbra

Problems about rates?

Answer 1

Based on the information John can do 1/5 of the task per hour

Steve can do 1/4 of the task per hour

So, in 2 hours working together

John & Steve can do 2( 1/5 + 1/4 ) = 9/10 of the task

Since John is left to finish, Let x = the time it takes him to finish

Then,

1/5 task/hour = 1/10 task/x hours Solving for x

x = 1/2 hour

So John takes another 30 minutes after Steve leaves!