Question

Twenty dots will cover one square inch. If a floor measures $5$ feet by $2.5$ feet, how many dots does it take to cover the floor?

• A. $1,800$
• B. $15,000$
• C. $36,000$
• D. $45,000$

Answer 1

Answer: (C)

$36,000$

Area of floor $=$ $5\times 25=12.5$ sq.feet

1 sq.feet $=144$ sq.inch$\Rightarrow$ $12.5sq.ft=144$$\times$$12.5$ sq.in

$1$ sq. in covered by $20$ dots, then $144$ $\times$ $12.5$ sq. in covered by

$=144$ $\times$ $12.5$ $\times$ $20=36000$ dots