Question

The length, breadth and thickness of a metal block is given by $l=9\text{cm},b=8\text{cm},t=2.45\text{cm}$. The volume of the block is (consider the concepts of significant digits)

• A. $2\times {10}^2{\text{cm}}^3$
• B. $1.8\times {10}^2{\text{cm}}^3$
• C. $1.77\times {10}^2{\text{cm}}^3$
• D. $1.764\times {10}^2{\text{cm}}^3$

Answer 1

The correct option is A $2\times {10}^2{\text{cm}}^3$

$V=l\times b\times t$
$V=9\times 8\times 2.45$
$V=176.4{\text{cm}}^3=1.764\times {10}^2{\text{cm}}^3$
After multiplying, we select the number which has least significant digits and we will express the answer in same significant digits. So, when we round off the answer we will get -
$=2\times {10}^2{\text{cm}}^3$