me speed = 60 mi/h
grandparents speed = 75 mi/
distance = 288
Formula
speed = distance/ time
me distance x grandparents distance = 288 - x
distance traveled in 1 hour 75 =( 288 - x) / t
t = (288 - x) / 75
distance = 60 x 1 = 60
x = 60 + 60t
x - 60 = 60t
t = (x - 60)/60
(x - 60)/60 = (288 - x) / 75
75(x - 60) = 60(288 - x)
75x - 4500 = 17280 - 60x
75x + 60x = 17280 + 4500
135x = 21780
x = 21780/135
x = 161.3 mi
Time
t = (161-3 - 60)/60
t = 101.33/60
t = 1.7 h
1 h -------------------- 60 min
1.7 h ------------------ x
x = (1.7 x 60)
x = 101.3 min
total time = 1 h and 41 min
They will meet at 1:41 am