Question

Cards marked with the number $2$ to $101$ are placed in a box and mixed thoroughly. One card is drawn from the box. Find the probability that the number on the card is:

1 An even number

2 A number less than $14$

3 A number is perfect square

4 A prime number less than $20$

• A. $1:\frac{1}{2},2:\frac{3}{25},3:\frac{9}{100},4:\frac{2}{25}$
• B. $1:\frac{1}{2},2:\frac{4}{25},3:\frac{3}{10},4:\frac{2}{25}$
• C. $1:\frac{1}{2},2:\frac{2}{25},3:\frac{1}{10},4:\frac{3}{25}$
• D. $1:\frac{1}{5},2:\frac{3}{25},3:\frac{1}{10},4:\frac{2}{25}$

Answer 1

The correct option is A $1:\frac{1}{2},2:\frac{3}{25},3:\frac{9}{100},4:\frac{2}{25}$

1)Number on cards are 2 to 101

Even number are 2,4,6,..,100=50

Probability that it's an even number =50/100=1/2

2)Numbers less than 14 are 2,3,4,5,6,7,8,9,10,11,12,13=12

Probability=12/100=3/25

3) Perfect square are=4,9,16,25,36,49,64,81,100=9

Probability=9/100

4) Prime number less than 20 are 2,3,5,7,11,13,17,19=8

Probability=8/100=2/25