Answer: Let's call the number of marbles that Kayla gets x. Then, Leanne gets 3x marbles. The total number of marbles that the girls receive is x + 3x = 4x, so 4x must equal 42 marbles:
4x = 42
Dividing both sides by 4:
x = 10.5
Since the number of marbles that each girl receives must be an integer, we round down to the nearest whole number. So, Kayla gets 10 marbles and Leanne gets 3 * 10 = 30 marbles.
Explanation: