Question

If 36 workers can build a wall in 12 days, how many days will 16 workers take to build the same wall? (Assuming the number of working hours per day is constant)

• A. 27 days
• B. 25 days
• C. 28 days
• D. 30 days

Answer 1

The correct option is A 27 days

If the number of workers decreases, the time to taken built the wall increases in the same proportion. Clearly, number of workers varies inversely to the number of days.
So here $\frac{x_1}{y_1}=\frac{x_2}{y_2}$
where
$x_1$​=36 workers,
$y_1$=12 days
$x_2$​=16 workers and
$y_2$​=? days
Substitute, $\frac{36}{16}=\frac{y_2}{12}{y}_2=27$
Therefore 16 workers will build the same wall in 27 days.