Question

Roger can shovel his family's driveway in 1 hour. His older sister, Alexis, can shovel the driveway in 1/2 hour. If they work together, then how many minutes will it take them to shovel the driveway?

Answer 1

90 mins

Explanation:

1 hour =60 mins

1/2 hour = 60/2=30

so, 60 +30=90

Answer 2

40 min

Explanation:

his sister can do it twice as fast so the boy does 1 and the sister does 2. he will do 1/3 of the work and it will take 1/3 of the time