Question

Please help!?

A manufacturer of automobiles conducted a market survey. `80%` of the customers want better fuel efficiency, while `55%` want a vehicle navigation system and `45%` percent want both features.
The probability that a person wants either better fuel efficiency or a vehicle navigation system is:

`a)0.35`
`b)0.9`
`c)0.40`
`d)0.1`

Answer 1

Probability is `0.90` and answer is `(b)`.

Explanation:

As `80%` of the customers want better fuel efficiency and `45%`
want both features, `80%-45%=color(red)(35%)` want only better fuel efficiency.

Similarly as `55%` want a vehicle navigation system and `45%`
want both features, `55%-45%=color(red)(10%)` want only vehicle navigation system.

Hence `35%+10%+45%=90%` want either better fuel efficiency or a vehicle navigation system and

Probability is `90/100=0.90` and answer is `(b)`.