At first, a bucket contained
15 ℓ of water. Tammy added another
13 ℓ of water into the bucket. Then she used
78 of all the water in the bucket. How much water did Tammy use? Express your answer as a fraction in its simplest form.
Total volume of water in the bucket after Tammy added more water into the bucket
= 15 + 13
= 315 + 515
= 815 ℓ
8 u = 815
1 u = 815 ÷ 8 = 815 x 18 = 115
Volume of water that Tammy used
= 7 u
= 7 x 115
= 715 ℓ
Answer(s): 715 ℓ