O-level Mathematics june 09 paper 1 questn 8

[dasani]

8 A bag contains red, green and yellow pegs.
A peg is taken at random from the bag.
The probability that it is red is 0.35 and the probability that it is green is 0.4.
(a) Find the probability that it is
(i) yellow,
(ii) not red.
(b) Originally there were 16 green pegs in the bag.
Find the total number of pegs.


help in this question.

 

[Angraiz]

a) i) probability of all colours = 1. So probability of yellow = 1 - 0.35 - 0.4 = 0.25
ii) 1 - probability of red = 1 - 0.35 = 0.65

b) probability of green peg = number of green pegs/total pegs
Total pegs= 16/0.4 = 40

 

[dasani]

thanks