# Question #8e7e7

Sep 12, 2016

(A) Fuel efficiency or gas mileage $= \text{Distance traveled"/"Gas used}$
Plugging in given numbers we get

Fuel efficiency or gas mileage $= \left(400 \text{ miles")/(15" Gallon}\right)$

Converting miles to km and gallons to litres we get

Fuel efficiency or gas mileage $= \left(400 \times 1.60934 \text{ km")/(15xx3.78541" litres}\right)$
$= 11.34 \text{ km/l}$, rounded to two decimal places.
(B) $\frac{1}{2}$ pound of tea leaves give $30$ cups of tea.
$\implies 1$ pound of tea leaves give $30 \times 2 = 60$ cups of tea.

Converting pounds to gram and cups to ml, we get
$1 \times 453.592$ gm of tea leaves give $60 \times 236.588237$ ml of tea.
$\implies 1$ gm of tea leaves give $\frac{60 \times 236.588237}{453.592}$ ml of tea.
$\therefore 0.5$ gm of tea leaves give $\frac{60 \times 236.588237}{453.592} \times 0.5$ ml of tea.
$\implies 0.5$ gm of tea leaves give $15.6$ ml of tea, rounded to one decimal place.