Question

Some of the children at a school arrive by car.

30% of the children at the school are boys
60% of the boys at the school arrive by car
80% of the girls at the school arrive by car
what is the probability that a child chosen at random from the school arrives by car? give your answer as a decimal

Answer 1

0.74

Explanation:

30% boys

So 100-30 = 70% girls

(60% × 30%) + (80% × 70%)

0.74

Answer 2

the probability that a child chosen at random from the school arrives by car is 0.74 .

Explanation:

Here we have , Some of the children at a school arrive by car.

30% of the children at the school are boys

60% of the boys at the school arrive by car

80% of the girls at the school arrive by car

We need to find what is the probability that a child chosen at random from the school arrives by car .Let's find out:

Probability of child to arrive by car = Probability of a girl to arrive by car + Probability of a boy to arrive by car

⇒ Probability of a boy to arrive by car =
`(3)/(10) ((6)/(10) )`

⇒ Probability of a boy to arrive by car =
`(18)/(100)`

⇒ Probability of a boy to arrive by car =
`0.18`

Also , Probability of a girl to arrive by car =
`(7)/(10) ((8)/(10) )`

⇒ Probability of a girl to arrive by car =
`0.56`

Putting these values we get:

⇒
`Probability = 0.56+0.18`

⇒
`Probability =0.74`

Therefore , the probability that a child chosen at random from the school arrives by car is 0.74 .