We can write it down as:
Jill = x
Ned = 1,5 * x
Tom = x + 15
So:
190 = x + 1,5 * x + x + 15
190 = x + 1,5x + x + 15
190 = 2x + 1,5x + 15
190 = 3,5x + 15 / - 15 (both sides)
175 = 3,5x / ÷ 3,5 (both sides)
x = 50
So:
Jill = 50 kg
Ned = 1,5 * 50 = 75 kg
Tom = 50 + 15 = 65 kg
