Question

Gabbar watched 650 movies in the last 5 years. Every year he watched 10 movies less than the previous year. How many movies did he watch in the 1st year?

Answer 1

he watched 2movie in 1st year

Answer 2

This is a Arithmetic Series.
Sum = n/2[2a + (n - 1)d]
5/2(2a + 4 x -10) = 650
2a - 40 = 650 x 2/5 = 260
2a = 260 + 40 = 300
a = 150

He watched 150 movies in the first year.

The series is 150 + 140 + 130 + 120 + 110 = 650