Question

Cards marked with number 2 to 101 are placed in a box and mixed thoroughly. One card is drawn from this box. Find the probability that the number on the card is (a) not a number which is a perfect square.(b) a 2-digit number in which the sum of digits is 9.

Answer 1

Step-by-step explanation:

Total number of cards = (101-2) + 1 = 100

a) Numbers which are perfect squares:

4, 9, 16, 25, 36, 49, 64, 81, 100

Thus there are 9 numbers which are perfect squares.

Probability that the number drawn is not a perfect square will be:

$1 - \frac{9}{100} = \frac{91}{100}$

b) 2 digit numbers with a sum of 9:

18, 27, 36, 45, 54, 63, 72, 81, 90

Thus there are 9 numbers.

Probability that the number drawn is a 2 digit number in which the sum of digits is 9:

$\frac{9}{100}$