Hi, I got the following problem from a GRE book. They have provided a method but i am trying to solve it using a different method. My answer is wrong. Q.A jar contains 10 red marbles & 30 green ones. How many red marbles must be added to the jar so that 60% of the marbles will be red? Sol. Current percentage of red marbles is: 10/40 * 100 = 25% This means we have to add 35% more red marbles: x/(x+40) * 100 = 35 100x = 35x + 1400 65x = 1400 X= 22 (Answer is not correct). Some body please guide me what is my mistake. Zulfi.