A) \[680\,\,km/h\]
B) \[360\,\,km/h\]
C) \[320\,\,km/h\]
D) \[640\,\,km/h\]
Correct Answer: A
Solution :
Let the speed of one plane be \[x\]km/hour, Then the speed of other plane is \[(x+40)\,km/hour.\] Distance travelled by first plane in 5 hours = \[Speed\times Time=x\times 5=5x\] Distance travelled by second plane in \[5\,\text{hours}=(x+40)5.\] Distance travelled by first plane + Distance travelled by the other plane = 3400 km \[5x+5(x+40)=3400\] \[\Rightarrow \]\[x=\frac{3200}{10}=320km/\text{hour}\] Sum of speeds = (320 + 360) km/h = 680 km/hourYou need to login to perform this action.
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