If x:y=7:4 and x + y = 88, work out the value of x – y.

Total of parts: 7+4=11therefore if we divide 88 in 11 “parts” we get each part as 8.hence if x corresponds to 7 parts then x=8X7=56 and if y corresponds to 4 “parts” y=4X8=32THEREFORE: x-y=56-32=24