Pls help mathswatch attachment

Which of the following contains a variable?

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min. if they did not stop driving, how many miles could kyle and elijah drove in a whole day? ? 1 day = 24 hours. plzzz write a proportion i will give you 100 points

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.