Tank E and Tank F had some oil in the ratio 7 : 5. After 42 litres of oil was transferred from Tank E to Tank F, the volume of oil in Tank F became 2 times as much as in Tank E. How much oil were there in the two tanks in all?
| |
Tank E |
Tank F |
Total |
Before |
7x1 =
7 u |
5x1 =
5 u |
12x1 =
12 u |
| Change |
- 42 |
+ 42 |
|
After |
1x4 =
4 u |
2x4 =
8 u |
3x4 =
12 u |
The total volume of oil in the tanks remained unchanged. Make the total volume at first and in the end the same. LCM of 3 and 12 is 12.
Amount of oil transferred from Tank E to Tank F
= 7 u - 4 u
= 3 u
3 u = 42
1 u = 42 ÷ 3 = 14
Total volume of oil in two tanks
= 12 u
= 12 x 14
= 168 ℓ
Answer(s): 168 ℓ
