Pawnee and Springfield are 420 miles apart. A train leaves Pawnee heading to Springfield at the same time a train leaves Springfield heading to Pawnee. One train is moving at a speed of 45 mph, and the other is moving 60 mph. How long will they travel before they meet?

解

P a w n ee an d Sp r in g f i e l d a re 420 mi l es a p a r t . A t r ain l e a v es P a w n ee h e a d in g t o Sp r in g f i e l d a t t h e s am e t im e a t r ain l e a v es Sp r in g f i e l d h e a d in g t o P a w n ee . O n e t r ain i s m o v in g a t a s p ee d o f 45 m p h, an d t h e o t h er i s m o v in g 60 m p h . Ho w l o n g w i ll t h ey t r a v e l b e f ore t h ey m ee t ?

time : 4

解答ステップ

Translate the problem into an equation:

45 x + 60 x = 420

x

を解く

45 x + 60 x = 420 : x = 4

time : 4