Noah has 2 tanks. Tank Q and Tank R are of different capacities. If Tank Q is filled by a tap at a rate of 3 litres per minute and Tank R is filled by a tap at a rate of 7 litres per minute, when Tank Q is completely filled, 6 litres of water flowed out from Tank R. If Tank Q is filled by a tap at a rate of 4 litres per minute and Tank R is filled by a tap at a rate of 3 litres per minute, when Tank Q is completely filled, Tank R is only half-filled. What is the capacity of Tank R? Express your answer in litres.
|
Scenario 1 |
Scenario 2 |
Tank type |
Tank Q |
Tank R |
Tank Q |
Tank R |
Volume of the tank |
3 u |
7 u - 6 |
4 p |
3 p x 2 = 6 p |
Let 1 u be the time taken for Scenario 1.
Let 1 p be the time taken for Scenario 2.
3 u = 4 p --- (1)
7 u - 6 = 6 p
7 u = 6 p + 6 --- (2)
Make u the same.
(1) x 7
21 u = 28 p --- (3)
(2) x 3
21 u = 18 p + 18 --- (4)
(3) = (4)
28 p = 18 p + 18
28 p - 18 p = 18
10 p = 18
1 p = 18 ÷ 10 = 1.8
Volume of Tank R
= 6 p
= 6 x 1.8
= 10.8 ℓ
Answer(s): 10.8 ℓ