Question

Ben is traveling home on M1 and M42 both motorways have roadworks he has fifty-fifty chance of getting delayed on the M42 and 75% chance of being delayed on the M1. What are the chances he will not be delayed on his journey?

1 in 4

3 in 8

1 in 8

1 in 2

Please show your working out

Answer 1

P(being delayed on M1) = 0.5 →P(NOT being delayed on M1) = 1-0.5 = 0.5

P(being delayed on M42)=0.75→P(NOT being delayed on M42) = 1-0.75= 0.25

P(NOT being delayed on M1) AND P(NOT being delayed on M42) = 0.5x0.25
→ 0.125 = 1/8

So, the chances he will not be delayed on his journey is 1/8