Question 381516
Enrique cycled to his grandmother's house at 15 kph and returned home over the same route at 18 kph. If the whole trip took 7 hrs. and 20 min., how far does Enrique live from his grandmother's house? 

-----------------
To Grandmother's DATA:
rate = 15 kph ; distance = x km ; time = x/15 hrs
----------------
From Grandmother's DATA:
rate = 18 kph ; distance = x km ; time = x/18 hrs
-----------------------
Equation:
time + time = 7 1/3 hrs.
----
x/15 + x/18 = 22/3
----
Multiply thru by 90 to get:
6x + 5x = 660
11x = 660
x = 60 km (distance to Grandmother's)
========================================
cheers,
Stan H.