Answer:
(0.118, 4.882)
Explanation:
If a motorist drives for m hours at 120km/hr, then the Distance of the motorist is expressed as;
Distance = Speed * time
da = 120m
If he drives n hours at 18km/hr;
db = 18 * n
db = 18n
Speed of the motorist altogether is expressed as;
Speed =78km/5hrs
Speed = 15.6km/hr
SInce the total distnce is 78km
120m + 18n = 78 ....1 ..... * 1
If total time is 5hrs
m + n = 5....2 ...*18
Solve simultaneously
120m + 18n = 78
18m + 18n = 90
Subtract
120m - 18m = 78-90
102m = -12
m = 0.118 hrs
m =
Since m + n = 5
n = 5 - m
= 5 - 12/102
n = 4.882
Hence (m,n) is (0.118, 4.882)