Question

Problems on Quadratic Equations.
Question No. 26,27 &28​

Answer 1

Answer:

Step-by-step explanation:

26.Let

speed of express train =x km/hr

d=240 t=240/x hr

speed of ordinary train=x-12 km/hr

t=240/x-12 hr

ATQ:-

(240/x-12)-240/x=1

on solving:

x=60 km/hr.

27.

D=400km

let original sped=x km/hr

time=400/x hr

No,s=12+x km/hr

t=400/12+x hr

ATQ;-

(400/x)-(400/12+x)=1hr40min

(400/x)-(400/12+x)=5/3 hr

on solving:-

x=48 km/hr

28.

d=400km

s=x km/hr

now

s=x=40 km/hr

i.t=400/x hr

ii.t=400/x+40 hr

iii.ATQ:-

(400/x)-(400/x+40)=30/60 hr

on solving:

x=160 km/hr