Question

a plane left 30 minutes late that scheduled time and in order to each the destination 1500 km away in time it had to increase its speed by hundred kilometre per hour from the usual speed find the usual speed

Answer 1

is it from leaked paper

Answer 2

Let the usual speed of the plane be x km/h
Time taken to cover 1500 km with the usual speed =1500/x hrs
Time taken to cover 1500 km with tje speed of (x+100)km/hr=1500/x+100hrs
1500/x=1500/x+100+1/2
=1500/x - 1500/x+100=1/2
1500x+1500×100 - 1500x/ x(x+100)=1/2
1500×100/x×x+100x =1/2
300000=x×x+100x
x×x+100x - 300000=0
x×x+600x - 500x - 300000=0
X(x+600) -500(x+600)=0
X+600=0 or x - 500=0
×= - 600 or x=500
Since speed cannot be negative
X= 500 km/ hr