Question 204475
rate of the bus = B
rate of the cyclist = C
distance traveled = 90 miles
time taken by the bus = 90/B
time taken by the cyclist = 90/C


B = 3C
90/C = 4 + 90/B
90/C = 4 + 90/(3C)
90/C = 4 + 30/C
90/C - 30/C =4
60/C = 4
C = 60/4 = 15
B = 3C = 3*15 = 45


so,the rate of the bus is 45 miles/hour