Steve has bought a pair of speaker stands. the base of each stand is a hollow prism with the dimensions shown. a hollow tube of diameter 4cm and height 110cm screws into the top of each base to form a stand. steve is filling the stands with sand to improve stability. find the volume of sand steve needs to use to fill both stands (the bases and the tubes) give your answer in litres to 2d. p

Ascientist places 24 cells in a petri dish. she knows the cells grow at an exponential rate, doubling in number every hour. how long will it take (in hours) for there to be 1100 cells in the dish? time to 1100 cells: 5.51832530 hours how long will it take to reach 110 cells? time to 110 cells : 2.1963972 hours what is the average rate of change in the number of cells between 9 hours and 11 hours? average rate of change: cells per hour what is the instantaneous rate of change after 7 hours? instantaneous rate of change: cells per hour note: you can earn partial credit on this problem.