Question

A biker can ride a bicycle 18 miles in 3 hours. the messenger estimates that it will take 7 hours to bike 22 miles. here is the messengers work:

step 1: 22-18=4


step 2: 3+4=7


what mistake did the messenger make?


• the messenger did not make a mistake. the estimate is correct


• the 3 and 4 should have been multiplied instead of added.


• the messenger used addition and Subtraction instead of multiplication and division


• the 22 and 18 should have been divided instead of subtracted


• the 22 and 18 should have been averaged instead of subtracted

Answer 1

The messenger should use addition and Subtraction instead of multiplication and division

Explanation:

It is given that,

A biker can ride a bicycle 18 miles in 3 hours. the messenger estimates that it will take 7 hours to bike 22 miles.

He has done two steps :

step 1: 22-18=4

step 2: 3+4=7

The steps done by the biker are wrong. The correct step should be :

In 1 hour, he should cover (18/3) miles i.e. 6 miles

In 7 hours, he will cover (6×7) miles i.e. 42 miles

It means he should use addition and Subtraction instead of multiplication and division. Hence, the correct option is (c).