Mr Chua borrows a sum of money from the bank which charges a compound interest of 4.2% per annum, compounded quarterly. Given that Mr Chua had to pay $96.60 in interest payments at the end of the first year, find their original sum of money borrowed, giving your answer correct to the nearest cent.

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 3 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 3 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.