Two medical representatives leave a hotel at the same time but travel by car in opposite directions. Rolly's average speed is 3kph faster than Jauncho's. Find their rates of speed if after 5 hours, they are 455kph.

Help po proper answer po sana. Thank you!


Sagot :

Let:

Rolly's speed = SR

Juancho's speed = SJ

Distance = Speed x Time -- equation 1

Since they are travelling on opposite direction:

Distance of Rolly + Distance of Juancho = 455km

DR + DJ = 455

Substitute using equation 1

(SR)(Time) + (SJ)(Time) = 455

Time = 5 hrs

5SR + 5SJ = 455

SR + SJ = 91 -- equation 2

Also, we know that Rolly's speed is 3 kph faster than Jauncho's, therefore:

SR = SJ +3 -- equation 3

Substituting equation 3 in equation 2:

(SJ + 3) + SJ = 91

2SJ = 88

SJ = 44 kph

SR = SJ + 3

SR = 44 + 3 = 47 kph