Question

In a group of 33 pupils, 1 plays the flute only.

12 play the piano only.
10 play neither instrument.
A student is selected at random.
What is the probability the student plays both instruments?

Answer 1

0.303

Explanation:

The number of students who plays both flute and Piano can be obtained thus :

Let numbwr who plays both =x

Piano only + flute only + both + neither = total

12 + 1 + x + 10 = 33

23 + x = 33

x = 33 - 23

x = 10

Hence, probability that student plays both instrument :

P = required outcome / Total possible outcomes

P(plays both) = 10 / 33 = 0.303