Percent increase in the numbers of cars washed is 75%
<u>Step-by-step explanation:</u>
<u>Given:</u>
Number of cars washed in First weekend by the students =40 cars
Number of cars washed in second weekend by the students= 70 cars
To Find:
Percentage of increase in the number of car washed=?
Solution:
we know that
Percentage Increase=Final Value−Starting Value|Starting Value x 100
According to our question

Substituting the values,
percentage of increase in the cars =
percentage of increase in the cars =
percentage of increase in the cars =
percentage of increase in the cars =75