Question 541112
let the target be at distance x 

both arrive at same time

time taken by bomber = x/400

time taken by jet = x/500

jet took 1/2 hour less than bomber

x/400 -x/500=1/2

LCD=2000
multiply the equation by LCD
x*2000/400 - x*2000/500 = 1*2000/2

5x-4x=1000
x= 1000 
speed of jet = 500 mph
Time taken by Jet = 1000/500= 2 hours
....
Time taken by Bomber = 1000/400 = 2.5 hours

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