Question

an aeroplane left 40 minutes late due to heavy rains and in order to reach its destination 1600 km away in time. it has increase its speed by 400 km per hour from its usual speed. find the original speed of the aeroplane.​

Answer 1

Step-by-step explanation:

let speed= X km/ h

increased speed =( X+400) km / h

ACC to question

1600+160000/(X)(X+400)=1600x=1/2 320000=x^2+400x

x^2+400x=320000

x^2+800x+400x-320000

x(X+800)-400(X+800)

(x-400) (X+800)

x=400 , X=-800

speed cannot be negative

so X=400km/ h