Food grains are to be sent to city from go down. Owner wants to reach the food grains at 11 O' Clock in the city. If a truck travels at a speed of 30km/hr then he will reach the city one hour earlier. If the truck travels at a speed of 20km/h then he will reach the city one hour late. Find the distance between the go down to city. Also with which speed the truck should travel in order to reach at exactly 11 'O clock.

• Let distance be x km and original time be t hr, when he travels at constant speed, say s kmph.
  Clearly, x = st.
  Now, x=30(t-1) and x=20(t+1). Solving these to simultaneous linear eqns, we get x=120 km and t=5 hr. So, distance between city and go-down=120km. To reach exactly at 11 o'clock, he must travel at speed s=x/t = 120/5 = 24 kmph
• 15 years agoHelpfull: Yes(8) No(1)
• (x/20)-(x/30)=2
  x=120km
  
  to reach at 11 o'clock
  
  5hrs-->120km
  so speed needed :120/5=24kmph
• 8 years agoHelpfull: Yes(2) No(0)
• 24 km/hr
• 15 years agoHelpfull: Yes(0) No(0)