supiya runs a race in 50 minutes at an avg speed of 48km/hr in order to set a national record she needs to win the race in 40 minutes.what is the minimum speed to set the record
a.70km/hr
b.60km/hr
c.55km/hr
d.50km/hr

• ans :b
  50 avg speed is 48km/hr for 1 hour 48 km for 50 mints 5/6*48=40
  d=vt
  40=v*4/6
  v=60km/hr
  
• 9 years agoHelpfull: Yes(0) No(0)
• b. 60 km/hr
  
  Distance covered(in Km) in 50min= 48*50/60=40 Km.
  So minimum speed required to to cover 40 Km. in 40 min=40/(40/60) =60 km/hr
• 9 years agoHelpfull: Yes(0) No(0)