Answer: 52.94
Step-by-step explanation:
Length of train A = 480m
Tunnel length = 1320m
Time taken to cross tunnel = 2 mins = 120sec
Length of train B = 420m
Train B is slower than train A
Difference between their speed = 18km/hr
18km/hr = (18×1000)/3600 = 5m/s
Speed of train A :
Speed = distance / time
Speed = 1320 / 120 = 11m/s
Therefore, speed of train B :
(11 - 5)m/s = 6m/s
Relative speed of the two trains is therefore;
(Speed of A + speed of B)
Note : they are moving in opposite direction
( 11 + 6)m/s = 17m/s
Therefore time taken to cross each other :
(Sum of the length of both trains / relative speed of the trains)
Time taken = (480m + 420m) / (17m/s)
Time taken = 900m / 17m/s
Time taken = 52.94s
Answer:
a 30 b -21
Step-by-step explanation:
a 5x = 5(6)
= 30
b 3y = 3(-7)
= -21
Multiplying a number by 4/5 and then dividing by 2/5 is the same as multiplying by 2
Answer: Joey is faster
Step-by-step explanation: Because in 1 hour Joey is run 4 mile but in 1 hour Chandler is run 2 mile
