Solution: χ+25%χ=7.2 Solution: 1-85% χ = 0. 15 Solution: 45%χ+ 15%χ= 1.92.

1.25χ=7.2 0. 15χ=0. 15 0.6χ= 1.92

χ=5.76 χ= 1 χ=3.2