A student cycles for xhours at 12km/hr and y hours at 16km/hr.Altogether,the student cycles 66km/hr in 5hrs.find the values of x and y

5 answers

The way you typed it makes no sense.
Did you mean he biked 66 km in 5 hrs ?

I will assume that.

distance covered at 12 km/h = 12x km
distance covered at 16 km/h = 16y km

12x + 16y = 66
6x + 8y = 33

x + y = 5
y = 5-x

plug this into the other equation:
6x + 8(5-x) = 33
6x + 40 - 8x = 33
-2x = -7
x = 3.5
then y = 1.5
how is y =1.5
how did y become 1.5
Why is y = 1.5
seems y=5-x so is going to become y=5-(3.5)
y=1.5