Question 1185707

Andrew, Benny and Calvin were given a box of marbles. Andrew took 1/4 of the marbles and then took another 6 marbles from the box. Benny took 1/6 of the remaining marbles and then took another 5 marbles from the box. Calvin took the remaining 45 marbles. How many marbles did Andrew take from the box?
<pre>Let original number of marbles be M
After Andrew took {{{1/4}}} of the marbles, and another 6 marbles, {{{matrix(1,3, (3/4)M - 6, or, 3M/4 - 6)}}} remained
After Benny took {{{1/6}}} of the remainder, and another 5 marbles, {{{matrix(1,7, 5/6, of, (3M/4 - 6) - 5, or, 5M/8 - 5 - 5, or, 5M/8 - 10)}}} remained
As 45 marbles remained in the end, we get: {{{matrix(1,3, 5M/8 - 10, "=", 45)}}}
5M - 80 = 360 ------ Multiplying by LCD, 8
5M = 440
Original number of marbles, or {{{matrix(1,5, M, "=", 440/5, "=", 88)}}}

Amount Andrew took: {{{highlight_green(matrix(1,5, (1/4) * 88 + 6, "=", 22 + 6, "=", 28))}}}</pre>