Question

$\sqrt{1225}=?$

• A. 25
• B. 45
• C. 55
• D. 15
• E. None of these

Answer 1

The correct option is E None of these

Here, to solve this, we use factorisation method.
So, $?=1225=5\times 5\times 7\times 7$
$\Rightarrow ?=\sqrt{1225}=\sqrt{\underset{–}{5\times 5}\times \underset{–}{7\times 7}}$
$\Rightarrow ?=\underset{–}{5\times 7}$ [$\because$ in square root, to remove root, we take pairs of two]
$\Rightarrow ?=5\times 7=35$