## Elementary Technical Mathematics

Mary needs to give $0.3$ grains.
RECALL: $P=BR$ where $B$=base, $P$=part, and $R$= rate or percent The given problem has: $B=0.75$ grains $R=40\%$ Solve for $P$ using the formula above to obtain: $P=BR \\P=40\% \times 0.75 \\P=0.40 \times 0.75 \\P=0.3 \text{ grains}$ Thus, Mary needs to give $0.3$ grains.