Arecipe calls for three cups of cheese to make nachos for six people .how much cheese is needed to make nachos for two dozen people?

Can someone check if i did this correct. it’s number 4 if you’re wondering.

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 the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie