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