A-and-B-are-two-towns-360km-apart-An-express-bus-departs-from-A-at-8a-m-and-maintains-an-average-speed-of-90km-h-between-A-and-B-Another-bus-starts-from-B-also-at-8a-m-and-moves-towards-A-making-fou

Question Number 66865 by John Kaloki Musau last updated on 20/Aug/19

A a n d B a r e t w o t o w n s 360 k m a p a r t .

A n e x p r e s s b u s d e p a r t s f r o m A a t

8 a . m a n d m a i n t a i n s a n a v e r a g e

s p e e d o f 90 k m / h b e t w e e n A a n d B .

A n o t h e r b u s s t a r t s f r o m B a l s o a t

8 a . m a n d m o v e s t o w a r d s A m a k i n g

f o u r s t o p s a t f o u r e q u a l l y s p a c e d

p o i n t s b e t w e e n B a n d A . E a c h s t o p

i s o f d u r a t i o n 5 m i n u t e s a n d t h e

a v e r a g e s p e e d b e t w e e n a n y t w o s t o p s

i s 60 k m / h . C a l c u l a t e t h e d i s t a n c e

b e t w e e n t h e t w o b u s e s a t 10 p . m .

Commented by John Kaloki Musau last updated on 20/Aug/19

T h e a n s w e r i s 65 k m .

p l e a s e d o i t .

Answered by John Kaloki Musau last updated on 20/Aug/19

d i s t a n c e t r a v e l l e d b y b u s 1

b e f o r e 10 a . m = 180 k m

d i s t a n c e t r a v e l l e d b y b u s 2

b e f o r e 10 a . m = 120 k m

120 k m o c c u s b t n d e p a r t u r e

p o i n t a n d f i r s t s t o p

1 s t s t o p = 5 m i n

10 a . m - 8 a . m - 5 m i n = 115 m i n

D = (\frac{115}{60} h r s \times 60 k m / h) k m = 115 k m

d i s t a n c e b t n b u s e s a t 10 a . m = {360 - (115 + 180)} k m

= 65 k m