Question

The amount of water in a bottle is reduced by 15% to 119 milliliters. How much water was originally in the bottle? ________ ml

Answer 1

Answer: 140 ml

Explanation:

let x be the original amount of water

x - 15% = 119
But x = 100% because it’s the original
=> 100% - 15% = 119ml
85% = 119ml

Find the amount of water in 15%:
85% = 119
15% = y

=> 85/15 = 119/y

Cross multiply:
85y = 15 x 119
85y = 1785
y = 1785/85
y = 21

But y = 15% therefore, 15% = 21ml

Back to our equation:
x - 15% = 119ml
x - 21ml = 119ml
x = (119 + 21)ml
x = 140ml

Therefore, the original amount of water is 140ml