Why is the remaining credit after 68 minutes of calls?

first of all the miniutes is not a linar function cause the first miniutes is 45 the 12 minuets later 57 but 11 minuets later 68 minuets so the minuets is not linear

what i did to find the credit was that i took 24.15-1.59 wich gave me 22.59 then i did 22.59-1.59 which gave me 21.03 if that is not correct

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.