Question

One test tube contains some acid and another test tube contains an equal quantity of water. To prepare a solution, 20 g of the acid is poured into the second test tube. Then, two-thirds of the so formed solution is poured from the second test tube into the first. If the fluid in the first test tube is four times that in second, what quantity of water was taken initially.

Answer 1

Let the initial amount of water taken be $x$ gm

According to question $x-20+\frac{2}{3}\times$ ($x+20$) = $4\times \frac{1}{3}\times$ ($x+20$)

Solving we get $x=100$gm

So initial amount of water taken = $100$ gm