Question

A survey was done of 160 households to find out if they watch cable television, internet television, or

both. Of the 160 households, 109 watched cable television, 88 watched internet television, and 7
watched neither. If a household was selected randomly, what would be the probability that they
watched both cable and internet television?
1) 0.175
2) 0.275
3) 0.375
4) 0.475​

Answer 1

Answer: 2) 0.275

Explanation:

Total households = 160

Watch Cable TV: 109

Watch internet TV: 88

Watch neither: 7

We want to find the number that watch both of them.

Now, the total number of housholds that watch at least one thing is:

160 - 7 = 153.

Now, if we add the number that watch by cable and the number that watch by internet we have:

109 + 88 = 197

The difference is:

197 - 153 = 44

This means that we have 44 households that watch both things.

This is because we are counting those 44 in the 109 for cable and also in the 88 for internet (because they watch both) and this is why we have a surpass.

Then the number that watch both things is 44, then the probability that a random household watched both things is equal to:

P = 44/160 = 0.275

The correct option is 2