Answer:
160 cars
Explanation:
The computation of the number of more cars he washed this year is given below;
Last year, he washed 20 cars a week so on yearly basis he washed
= 20 cars × 52 weeks
= 1,040 cars
And, this year he washed 1,200 cars
So, the number of more cars he washed this year is
= 1,200 cars - 1,040 cars
= 160 cars