Question

What is the least number of square tiles required to pave the floor of a room $15m17cm$ long and $9m2cm$ broad?

• A. $840$
• B. $841$
• C. $820$
• D. $814$

Answer 1

The correct option is B $841$

Let each side of the square tile be $xm$ and the number of tiles be $n$. Then,
$n{x}^2=1517\times 902$
$n{x}^2=2\times 11\times 37\times 41\times 41=841\times {41}^2$
$\Rightarrow$ Number of tiles $=841$ and length $=41cm$