Question

The announcer said, ‘Ingrid won the 100 metre race in 13.9 seconds.’

Her time was originally measured to 2 decimal places.

What was the slowest time she could have run?​

Answer 1

So the slowest time she could have run is 13.99 seconds, as any time greater than that would have been rounded up to 14 seconds.

Explanation:

Ingrid's time of 13.9 seconds was originally measured to 2 decimal places, which means that her actual time could be rounded to 13.9 seconds. To find the slowest time she could have run, we need to find the greatest value that could have been rounded down to 13.9 seconds.

Since the time was measured to 2 decimal places, this means that the hundredths place is known and the thousandths place can be anything between 0 and 9. So the slowest time she could have run is 13.99 seconds, as any time greater than that would have been rounded up to 14 seconds.