To find out how long it would take Danni to complete a 600 m race at the same rate, we first need to determine her speed based on the information given.
Danni drove 400 m in 5 seconds, so we can calculate her speed:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} = \frac{400 , \text{m}}{5 , \text{s}} = 80 , \text{m/s} \]
Now that we know her speed is 80 m/s, we can calculate the time it would take her to complete a 600 m race:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{600 , \text{m}}{80 , \text{m/s}} = 7.5 , \text{s} \]
So, if Danni drives at the same rate, she would be able to complete a 600 m race in 7.5 seconds.