Ken had some marbles. He gave 143 marbles to a friend and lost 1/4 of the remaining marbles. He was left with 1/5 of the total number of marbles he had at first. How many marbles had he left?
Call the total number of marbles m. So Ken is left with 3/4( m - 143) = 1/5 m. Multiply both sides by the LCM 20, and then simplify. Hope it helps you!