Please help its multiple choice

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 33 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30 ∘c on monday, but decreased at a constant rate in the next 33 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

9/10 divide by -3/15 as a mixed number