Practice | Hashtable

Home > Practice > Arithmetic Aptitude > Chain Rule > Miscellaneous

1. 4 persons can prepare an admission list in 8 days working 7 hours a day. If 3 persons join them so as to complete the work in 4 days, they need to work per day for ?

A. 6 hours

B. 8 hours

C. 10 hours

D. 12 hours

Solution:

Let the number of working hours per day be x
More persons, Less working hours ( Indirect proportion)
Less days, More working hours (Indirect proportion)

\begin{matrix} Persons   7 : 4 \\ Quantity  4 : 8 \end{matrix}} :: 7 : x

\begin{aligned} ∴ 7 \times 4 \times x = 4 \times 8 \times 7 \\ \Leftrightarrow x = \frac{(4 \times 8 \times 7)}{(7 \times 4)} \\ \Leftrightarrow x = 8 \end{aligned}

You must login to add comments. Login now.