The air force plane travelled for a total of 6.9 hours.
SOLUTION:
Given, An Air Force plane left Nairobi and flew west at an average speed of 159 mph. Â A cargo plane left sometime later flying in the same direction at an average speed of 207 mph. Â After flying for 5.3 hours the cargo plane caught up with the Air Force plane. Â
We have to find the number of hours the Air Force plane flew before the cargo plane caught up.
Now, we know that, [tex]\text { distance travelled }=\text { speed } \times \text { time }[/tex]
For air force plane [tex]\rightarrow \text { distance travelled }=159 \mathrm{x} \text { time taken by air force plane }[/tex]
[tex]\text { For cargo plane } \rightarrow \text { distance travelled }=207 \times 5.3 \text { hours }[/tex]
Now, when cargo plane caught the air force plane the distance travelled by the planes will be equal.
So, [tex]159 \times \text { time taken by air force plane }=207 \times 5.3[/tex]
[tex]\Rightarrow =\frac{207 \times 5.3}{159}[/tex]
[tex]\Rightarrow =\frac{1097.1}{159}[/tex]
Time taken by air force plane = 6.9 Â hrs
