Question

Having $5$ at units place, find the square of the number $185$.

• A. $34225$
• B. $48034$
• C. $15620$
• D. $83450$

Answer 1

Answer: (A)

$34225$

$185$ $=$ $(200-15)$

${185}^2$ $=$ $(200-15{)}^2$

$(200-15{)}^2$ $=$ ${200}^2$ $+$ ${15}^2$ $-$ $2\times 200\times 15$

${185}^2$ $=$ $40000$ $+$ $225$ $-$$6000$

${185}^2$ $=$ $34225$

Hence, Option A is correct.