Question

If 7 spiders make 7 webs in 7 days, then 1 spider will make 1 web in how many days?

• A. 1
• B. $\frac{7}{2}$
• C. 7
• D. 49

Answer 1

Answer: (C)

7

Let the required number days be $x$.
Less spiders, More days (Indirect Proportion)
Less webs, Less days (Direct Proportion)
$\begin{array}{cc}Spiders& 1:7\\ Webs& 7:1\end{array}\}::7:x$
$\therefore 1\times 7\times x=7\times 1\times 7$
$\Rightarrow x=7$