Barrel P and Barrel Q had some detergent in the ratio 7 : 5. After 30 litres of detergent was transferred from Barrel P to Barrel Q, the volume of detergent in Barrel Q became 2 times as much as in Barrel P. How much detergent were there in the two barrels in all?
| |
Barrel P |
Barrel Q |
Total |
Before |
7x1 =
7 u |
5x1 =
5 u |
12x1 =
12 u |
| Change |
- 30 |
+ 30 |
|
After |
1x4 =
4 u |
2x4 =
8 u |
3x4 =
12 u |
The total volume of detergent in the barrels remained unchanged. Make the total volume at first and in the end the same. LCM of 3 and 12 is 12.
Amount of detergent transferred from Barrel P to Barrel Q
= 7 u - 4 u
= 3 u
3 u = 30
1 u = 30 ÷ 3 = 10
Total volume of detergent in two barrels
= 12 u
= 12 x 10
= 120 ℓ
Answer(s): 120 ℓ
