Question

A, B and C can solve 50%, 60% and 70% of the sums from a book. If one sum from that book is given them to solve then  probability that the sum will be solved is _____

(a) 0.94

(b) 0.06

(c) 0.47

(d) None   

Answer 1

The correct option (a) 0.94   

Explanation:

P(A) = (50/100) = (5/10), P(B) = (60/100) = (6/10) and P(C) = (70/100) = (7/10)

A, B, C are independent events.

∴ P(A ∪ B ∪ C)   = 1 – P(A ∪ B ∪ C)'

= 1 – P(A') ∙ P(B') ∙ P(C')

= 1 – [(5/10)(4/10)(3/10)]

= 1 – (6/100)

= 0.94.