a box contains 100 cards marked with no. 1 to 100. if one card is drawn at random box , find the probability that no. on a card is 1 a multiple of 7 ,2 a no. smaller than 30
Answers
Answer:
There are 100 cards in the box marked with number 1 to 100.
A card is drawn randomly from it.
∴ Number of possible outcomes = 100
(1) Let A be the event that the card bears an even prime number.
There is only 1 even prime number from 1 to 100, that is '2'.
∴ The number of outcomes favourable to A is 1.
∴P(A)=1001=0.01
(2) Let B be the event that the card bears a number divisible by 7.
Numbers divisible by 7 from 1 to 100 are
7,14,21,28,35,42,56,63,70,77,84,91,98
There are 13 multiples of 7 from the numbers 1 to 100.
∴ The number of outcomes favourable to B is 13.
∴P(A)=10013=0.13
(3) Let be the event that the card bears a number that has 9 at the unit place.
The numbers from 1 to 100 that have 9 at the units place are
9,19,29,39,49,59,69,79,89,99
There are 10 numbers that have 9 at the unit place.
∴ The number of outcomes favourable to C is 10.
∴P(A)=10010=0.1