Question

Louisiana biologists tagged 250 fish in the oxbow lake False River on October 5. On a later date, they found 7 tagged fish in a sample of 350 fish. Estimate the total number of fish in False River to the nearest hundred.
At a school, the school population is 2/5 boys. There are 450 boys in the school. How many total students are in the school?

A bag contains quarter and dimes in a ratio of 3:5. If there is $6 in quarters in the bag, how many dimes are there?

Answer 1

1. Set up a ratio:

7 tagged / 350 fish = 250 tagged / x fish

Solve for x:

x = (350 * 250) / 7

x = 12,500 fish

2. Divide number of boys by the population ratio:

450 / 2/5 =  (450 *5) /2 = 2250 / 2 = 1125 total students.

3.  4 quarters = $1, so they have 24 quarters total.

The ratio 3:5 means for every 3 quarters there are 5 dimes.

24 quarters / 3 = 8

8 x 5 = 40 dimes.