Question

A survey on healthy choices was given to gym members at Work It Out. The results showed that 90% of its members drank protein shakes. Of the members who drank protein shakes, 30% took weight-loss medication whereas only 10% of members who did not drink protein shakes took weight-loss medication. What is the probability that a gym member does not take weight-loss medication?

Answer 1

72% of the gym members does not take weight-loss medication

Explanation:

Probability calculation

We'll solve this problem by pure logic and percentage calculations .

We know that 90% of the members of the gym drank protein shakes, which means that 10% did not drink protein shakes .

We also know that 30% of the members who drank protein shakes also took weight-loss medication.

It means that 30% of the 90% of the total members took weight-loss medication. 30% of 90% is (90%)(30%)=27%

We are also told that 10% of members who did not drink protein shakes took weight-loss medication. This 10% belongs to the original 10% who did not drink protein shakes. These members should be added up to the others who took weight-loss medication. 10% of 10% is (10%)(10%)=1%

The total percentage of members who took weight-loss medication is 27%+1%=28%

We are asked for the proportion of members who do not take weight-loss medication. It can be obtained by subtracting the previous percentage from 100%: 100%-28%=72%

Answer: 72% of the gym members does not take weight-loss medication