Question

Jacob can create an app in 24 hours, but if he works together with a friend they can create an app in 16 hours. How long would it take for his friend to create this app alone?

Answer 1

Time taken by his friend to create the app alone = 48 hours.

Explanation:

Hours needed by Jacob to create an app = 24 hours

`\text{One hour work of Jacob = }(1)/(24)`

Let hours needed by his friend in creating the app alone = x hours

`\text{So, one hour work of his friend = }(1)/(x)`

The both can create the app in 16 hours.

`\implies (1)/(24)+(1)/(x)=(1)/(16)\\\\\implies(1)/(x)=(1)/(16)-(1)/(24)\\\\\implies(1)/(x)=(24-16)/(24* 16)\\\\\implies (1)/(x)=(1)/(48)\\\\\bf\implies x = 48`

Hence, Time taken by his friend to create the app alone = 48 hours.