Please help me I don't understand this question

For 38 the average change is 30 ft per minute. just do 90 divided by 3. for 50, just add $4.50 to $65.50 five times and you get $90 after the 5 days

For number 50 that would be $90 because $4.50 is increasing over the five days so you have to multiply 4.50 x 5 then you get 22.5 finally you have to add 22.50 + 67.50 and you get $90.00