In A survey of 3005 adults ages 57 through 85 years it was found that 81.7% of them used at least one prescription medication. How many of the 3005 subjects used at least one prescription medication

So you have to figure out 81.7% of 3005.

3005 : 2 = 1502.5 = 50%

3005 : 5 = 601 = 20%

3005 : 10 = 300.5 = 10%

3005 : 100 = 30.05 = 1%

3005 : 1000 = 3.005 = 0.1%

Then you just add

1502.5 + (601 + 300.5) + 30.05 + (3.005 x 7)

1502.5 + 901.5 + 30.05 + 21.035

= 2455.085 (the answer)

The answer above is if you have a calculator/if it's a calculator question

Multiply 3005 by 0.817 to get your answer. Doing this gives you 81.7% of the total people surveyed which happens to be the amount of people who 'use at least one prescription medication' as outlined by the problem.