Mark ran for 15 minutes. How many seconds did Mark run? (1 minute = 60 seconds) seconds

Ineed to know the answer to this algebra question.

Suppose that a households monthly water bill (in dollars) is a linear function of the amount of water the household uses (in hundreds of cubic feet, hcf). when graphed, the function gives a line with slope of 1.65. if the monthly cost for 13 hcf is $46.10 what is the monthly cost for 19 hcf?

Find the value of x. round the length to the nearest tenth