Question

Exercise 4.2
1. Find the total distance in terms of x and y for each of the following:
(a) A car travels for x hours at 60km/h and y hours at 100 km/h.
(b) A person ran for 5 hours at x km/hr and 10 hours at y km/h.

Answer 1

Answer:

Speed=Dist/time

Dist=speed*time

a.Dist=60x+100y

b.Dist=5x+10y

Answer 2

Answer:

(a)60x+100y

(b)5x+10y

Step-by-step explanation:

(a) given,

time=x hours

speed=60km/hr

distance = time×speed

=x×60

=60x........(1)

in another case,

time=y hours

speed =100km/hr

distance = time×speed

=y×100

100y..........(2)

So,total distance=60x+100y (from(1) and (2))

(b) given,

time=5hours

speed=x km/hr

distance=time×speed

=5×x

=5x...........(1)

in another case,

time=10hours

speed=y km/hr

distance=time×speed

=10×y

=10y............(2)

So,total distance=5x+10y (from(1) and(2))