Question

When Nikki and Cara work together last year, they painted a fence in 8 hours. The previous year, Nikki painted the fence by herself. The year before that, Kara painted by herself, but took 12 hours longer. How long did it take Kara to paint the fence?​

Answer 1

Answer:

The answer to your question is letter D. 24 hours

Step-by-step explanation:

Data

Nikki + Kara = 8 hours

Kara = 12 hours

Nikki = ?

Process

1.- Calculate the time Nikki painted in 1 hour

Nikki and Kara painted the fence in 8 hours then, in 1 hour the painted 1/8    

Kara paint the fence in 12 hours then, in 1 hour she painted 1/12

The Kara painted in 1 hour:

                  Kara = 1/8 - 1/12

                  Kara = (3 - 2) / 24 = 1/24

2.- Calculate the time

Then in 1 hour she painted 1/24 of the fence, all the fence was painted in

      (1/24)24 = 1  which means 24 hours.