Let X be the total number of marbles Ken had at first.
After giving 143 marbles, he was left with X - 143 marbles.
Then he lost 1/4 * (X - 143) marbles.
So he was left with 3/4 * (X - 143) marbles.
And this was equal to 1/5 * X.
Therefore, 3/4 * (X - 143) = 1/5 * X.
Multiplying both sides by 20, we get:
15(X - 143) = 4X
Expanding the left side:
15X - 2145 = 4X
Subtracting 4X from both sides:
11X - 2145 = 0
Adding 2145 to both sides:
11X = 2145
Dividing both sides by 11:
X = 195
Therefore, Ken had 195 marbles at first.
After giving 143 marbles, he was left with 195 - 143 = 52 marbles.
Then he lost 1/4 * 52 = 13 marbles.
So he was left with 52 - 13 = 39 marbles. Answer: \boxed{39}.
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?
1 answer