Does anyone know what the answer to this practice quiz is? explain
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The average human heart beats 72 beats per minute. how many times does it beat in 15 seconds?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

What is x and y intercepts for y=x+7