Question

Question 37

Fill in the blanks to make the statements true.

There is a number in the box $\square$ such that, $\square ,24,9,12$ are in proportion.
The number in the box is ___.

Answer 1

Let the number in box be $x$

Then $x$, 24, 9 and 12 are in proportion.
$\therefore x:24::9:12$
$\Rightarrow \frac{x}{24}=\frac{9}{12}$ [$\because$ If a, b, c and d are in proportion, then $\frac{a}{b}=\frac{c}{d}$]
$\Rightarrow x\times 12=24\times 9$ [by cross multiplication]
$\Rightarrow x=\frac{24\times 9}{12}\Rightarrow x=2\times 9\therefore x=18$
$\therefore$ The number in the box is 18.