Question

A bus can cover a certain distance in 3 hours 20 minutes at an average speed of 45 km/h. how long will it take to cover the same distance at a speed of 36 km/h ?

A military camp has provisions for 630 men to last for 25 days. how many men must be transferred to another camp so that the food lasts for 30 days ?

plz explain with steps

Answer 1

let the distance travelled by the bus x
therefore, speed=distance/time
distance=speed*time
distance travelled=45*10/3.... [3hrs 20 mins=10/3 hours]
distance travelled=150km

time=distance/speed
time=150/36=25/6hours. (the answer can further be solved)

Q2. provision for 25 days= 630 men
this inverse variation
.. k=xy
. k=25*630

now let x be 30 days, therefore, y be no. of men
k=xy
25*630=30y
therefore, y=525men
men to be transferred=630-525=105men