Question

You and your friend Sam are going to paint your 300 square feet room together.

Sam takes 10 minutes to paint 25 square feet.
You take 5 minutes to paint 25 square feet.
Sam says, "If we paint together, then it will take us 15 minutes to paint 50 square feet!''
Write a EXCEPTIONAL explanation to convince Sam that he is wrong. Thank You.

Answer 1

Fraction that Sam painted in 1 min is:
10/25=2/5
Fraction that you painted in 1 min:
5/25=1/5

Fraction pained by both in 1 min:
1/5+2/5=3/5 ft²/min
Time taken to paint 50 ft² will be:
time=3/5×50=30 min
Thus we conclude that Sam was wrong.