Question

Today roberto mowed the lawn in 90 minutes.Every time he mows the lawn,he is able to decrease the amount of time it takes by 5%.How long will it take him to mow the lawn after he mows it 10 times

Answer 1

See below

Explanation:

Each time he mows is 95% of the previous time ...the first time is 90 minutes, then mow nine more times ...

90 ( .95)^9 = 56.72 minutes

Answer 2

100% - 5% = 95%

Multiply time by 95% raised to the number of times he will mow:

90 minutes x 0.95^10 = 53.88 minutes (round answer as needed)