Answer:
16
Explanation:
If 3/4 of a number is 15, we first want to calculate what 4/4 is (the original number).
to do this, first, we divide 15 by 3 to calculate 1/4 of the number.
(let me know if this step doesn't make sense)
15 ÷ 3 = 5
then multiply by 4 to find 4/4 of the number
5 × 4 = 20
therefore the full number is 20
we can verify this by quickly calculating 3/4 of 20 by multiplying by 0.75 (let me know if that doesn't make sense either)
20 x 0.75 = 15
no2 to calculate 4/5 of 20, we can either divide by 5 to find 1/5 and then multiply that by 4 to find 4/5, or we can more simply calculate 4/5 as a decimal and multiply that decimal by 20.
the long(er) way:
20 ÷ 5 = 4 (1/5 of 20)
4 x 4 = 16 (4 x 1/5 of 20)
therefore 4/5 of the number = 16
the short(er) way:
4/5 = 0.8 (this is the rate)
0.8 x 20 = 16
therefore 4/5 of the number = 16
hope this helps :)
let me know if there's anything you don't understand