Answer:
The number of boys who play tennis is 36.
Explanation:
Let the number of boys who play tennis is x.
number of boys who play cricket = y
x = 3 y..... (1)
12 boys plays both cricket and tennis.
According to the question,
x - 12 = y + 1 2
3 y - 12 = y + 12
2 y = 24
y = 12
So, the number of boys who plays tennis is x = 3 x 12 = 36.