Question

If $10$ workers can do a work in $15$ hours then $30$ workers can do it in _____ hours

• A. $5$
• B. $10$
• C. $15$
• D. $30$

Answer 1

The correct option is A $5$

This question is based on Inverse proprtion

According to the given conditions,

No. of workers Time taken

$10$ $15$ hours

$30$ $x$ days

By inversion proportion,

$10\times 15=30\times x$

$\therefore x=\frac{10\times 15}{30}$

$\therefore x=5$

Answer is $5$ hours