Question

MATHS GCSE
Sally plays two games against Martin.
In each game, Sally could win, draw or lose.
In each game they play,

the probability that Sally will win against Martin is 0.3
the probability that Sally will draw against Martin is 0.1

Work out the probability that Sally will win exactly one of the two games against Martin.

Answer 1

Answer:

Step-by-step explanation:

The probability that Sally will win against Martin is 0.3

the probability that Sally will draw against Martin is 0.1

the probability that Sally will win exactly one of the two games against Martin.

= 0.3 × 0.3

= 0.09

Tree diagram

Win =0.3

Draw= 0.1

Lose = 0.6

Answer 2

Step-by-step explanation:

so firstly we need to identify the probability of each which add up to one

win=0.3

draw=0.1

lose=0.6

now you could do a tree diagram but simply just identify the scenarios that have only one win. there are only 4:

.win+lose(0.3×0.6)

.lose+win(0.6×0.3)

.win+draw(0.3×0.1)

.draw+win(0.1×0.3)

now simply form a sum with the corresponding probabilities as above in brackets next to the scenarios

(0.3×0.7)+(0.7×0.3)+(0.3×0.1)+(0.1×0.3)

=0.18+0.18+0.03+0.03

=0.36+0.06

thus P=0.42

.