Time and Work Practice Test 1 with solutions

Work done by 14 persons in one day = $\frac{1}{27}$
Work done by 14 persons in 9 days = 9 $\times \frac{1}{27}$ = $\frac{1}{3}$
Work left = $\frac{2}{3}$
Remaining work can be done by 14 persons in 18 days.
Remaining work done by 1 person = (18 × 14) days.
∴ remaining work can be done by 21 persons in = $\left(\frac{18\times 14}{21}\right)$ days = 12 days