Question

An explorer is planning an expedition. He investigates three possible routes.
If he travels on route A which is 900 km long, he expects to cover x km per day.
Route B, which is the same distance as route A, has more difficult ice conditions and
he would only expect to cover (x – 7) km per day.
Route C, which is 100 km longer than route A, has easier conditions and he would
expect to cover (x + 7) km per day.
Write down an expression, in terms of x, for the number of days that he expects to
take on
i. Route A
ii. Route B
iii. Route C

Answer 1

Answer:

(I). Along route A,

distance= 900km

rate of covering the distance= x km/day

Let the no. of days taken by him to cover the distance be n.

a/q.

n× x= 900

then, n= 900/x

(ii) along the route B,

distance = 900km.

rate of covering the distance= (x-7) km /day

now ,let the no. of days required to cover the distance= N

a/q

N× (x-7)= 900

N = 900/(x-7)

(iii) along the route C,

distance =( 900+100)km= 1000km

rate of covering the distance= (x+7)km/day

similarly, let the no.of days required to cover the distance= N

then, N× (x+7) = 1000

so, N = 1000/(x+7)