Question

Beakers X and Y contain some water. If 50 ml of water is transferred from Beaker X

to Beaker Y, there will be 3/7 as much water in Beaker X as in Beaker Y. IF 100 ml
of water is transferred from Beaker Y to Beaker X, there will be 4 times as much
water in Beaker X as in Beaker Y. How much water is there in Beaker X?​

Answer 1

140 ml

Explanation:

Let x be the amount of water in Beaker X and y be the amount of water in Beaker Y.

Then we get following equations:

First part

• x - 50 = 3/7(y + 50)
• 7x -350 = 3y + 150
• 7x = 3y + 500

Second part

• x + 100 = 4(y - 100)
• x + 100 = 4y - 400
• x = 4y - 500

Substitute x in first equation:

• 7(4y - 500) = 3y + 500
• 28y - 3500 = 3y + 500
• 28y - 3y = 500 + 3500
• 25y = 4000
• y = 4000/25
• y = 160 ml

Then finding x:

• x = 4*160 - 500
• x = 640 - 500
• x = 140 ml

Initial amount of water in Beaker X is 140 ml, in Beaker Y is 160 ml