Question

A kilogram of whole-wheat flour costs $6. What is the cost of 400 grams of flower

Answer 1

$1 \ kg=1000 \ g \ - \ \ 6 \\ 400 \ g \ - \ x \\ \\ \frac{1000}{6}=\frac{400}{x} \\ 1000x=400 \times 6 \\ 1000x=2400 \\ x=\frac{2400}{1000} \\ x=2.4$

400 grams of flour cost $2.4.