1. If 36 donuts cost $15.00, what would be the cost for one 12 donuts?

$5 their are 36 donuts and 12 x 3 is 36 and 5 x 3 is 15

210 feet

Step-by-step explanation:

Lets say we start at 0 feet

Now all we gotta do is treat rising as addition and dropping as subtraction

0 + 400 = 400 - 90 = 310 + 100 = 410 - 200 = 210

Therefore your final height is 210. If you need further explanation just ask

A diagram is attached if you're still confused (Sorry about the quality, lightshot does not do curves well)