Question

The thickness of a dozen coins on a metre scale was found to be $18cm$. What is the thickness of one coin?

• A. $15cm$
• B. $1.2cm$
• C. $1.8mm$
• D. $15mm$

Answer 1

The correct option is D $15mm$

Number of coins, $n=12$
The thickness of a dozen coins, $t=18cm$

The thickness of one coin
$t^{\prime }=\frac{t}{n}$
$t^{\prime }=\frac{18}{12}$
$t^{\prime }=1.5cm=15mm$

$\because 1cm=10mm$