A highly volatile substance has an initial mass of 1200 g and its mass is reduced by 12% each second. a Write a formula that gives the mass of the substance (m) at time (t) seconds. b Rearrange this formula to make t the subject. C What mass remains after 10 seconds, correct to 2 decimal places? d Calculate how long (to the nearest second) it takes until the mass is 10 grams. e After how many seconds (to the nearest second) is the mass less than 1 gram?​