Question 18346
let x=cubes
so 3x is amount of longs
and flats=3x-30
put these together to total 600
x+3x+3x-30=600
7x-30=600 add 30 to both sides
7x=630 divide both sides by 7
x=90
so number of longs =3x = 3 X 90=270
270 longs
Pete