7. A train which is 100 meters long is traveling at a speed of 90 km per hour. How many seconds will it take for this train to pass completely through a 300 meter tunnel?
A 4
B 8
C 12
D 16
E 20

The answer is D, 16. How do you get 16 tho?

D; 16 seconds

Step-by-step explanation:

speed = distance/time

speed = 90 km/hr

We need to convert this to m/s because the tunnel is in meters and the time is in seconds:

distance = 300 m (tunnel) + 100 m (train) = 400 meters

Solving for time:

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour

make sure you have version 2.50

try looking in the very back of the book : )

step-by-step explanation:

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