Question

A box contains 120 discs which are numbered from 1 to 120. If

one disc is drawn at random from the box find the probability that it

bears. I) A two digit number ii) A perfect square number iii) A number

divisible by 9.​

Answer 1

Step-by-step explanation:

I) There are 100 two-digit numbers under 120.

thus there is a probability of 100/120

or, 5/6

or, 0.8333..

II) 1,4,9,16,25,36,49,64,81,100 are the only perfect square under 120

thus the probability is,

10/120

or, 1/12

III) 120/9 has a quotient of 13

thus there are 13 numbers divisible by 9

thus the probability is

9/120

or, 3/40