## Elementary Technical Mathematics

The base is the total length of the trip, which is the sum of the amount under VFR and the amount under IFR. $B=1.5+0.4=1.9$ hours The part is the amount of time flown under IFR, 0.4 hours. The rate is unknown. $R=\frac{P}{B}=\frac{0.4}{1.9}=0.2105$ To convert the decimal to a percent, move the decimal two places to the right. Round to the nearest tenth. $0.2105\approx21.1\%$