Amaya has an inflatable pool that she filled 3/4 full for her cousin on a hot summer day. After playing all day the pool was 3/10 full. How much of the water was lost.

3/7
1/6
9/20
18/40

To find the amount of water lost, we need to find the difference between the initial fill level and the final fill level.

Initial fill level: 3/4
Final fill level: 3/10

To find the difference, we subtract the final fill level from the initial fill level: 3/4 - 3/10

To subtract fractions with different denominators, we need to find a common denominator. The smallest common denominator for 4 and 10 is 20.

To convert 3/4 to twentieths, we multiply the numerator and denominator by 5: (3/4) * (5/5) = 15/20
To convert 3/10 to twentieths, we multiply the numerator and denominator by 2: (3/10) * (2/2) = 6/20

Now, we subtract 6/20 from 15/20: 15/20 - 6/20 = 9/20

Therefore, 9/20 of the water was lost. Answer: 9/20