Question

A boy played 100 games, gaining Rs 50 on each game that he won, and losing Rs 20 for each game that he lost. If on the whole he gained Rs 800, find the number of games that he won.

Answer 1

Let number of games won be x and number of games lost be y.
x + y = 100
y = 100 -x........(i)
Also given, Rs. gained = Rs.800
50x - 20y = 800
⇒ 5x - 2y = 80 .....(ii)
Substituting (i) 9n (ii)
5x - 2(100 - x) = 80
⇒ 5x - 200 + 2x = 80
⇒ 7x = 280
⇒ x = 40
Number of games won = 40.