Question

Ela can run $100$ metres in $20$ seconds. If she competes $400$ metres race, about how many seconds will it take her to run the race?

• A. $5$ secs
• B. $4$ secs
• C. $80$ secs
• D. $20$ secs

Answer 1

The correct option is C $80$ secs

Given that, Ela can run $100$100 metres in $20$20 seconds.

So, Ela can run $1$ metre in $\frac{20}{100}$ seconds.

So, for $400$ metres, Ela will take $\frac{20\times 400}{100}$ seconds, i.e $80$ seconds.

So, C is the right option.