Sameera is baking a birthday cake. H(t), She places the cake mix in a 180 preheated oven. The temperature in the centre of the cake mix in °C is modelled by the function H (t) = 180 + a (1.08) * where time t is in minutes after the mix is placed in the oven. The graph of H(t) is given. (a) The temperature in the centre of the cake mix was 22°C when placed in the oven. Find the value of a. (b) When will the cake reach 150°C. Give your answer correct to 3 sig figs. (b) The cake is removed from the oven 29 minutes after the temperature in the centre of the cake has reached 150°C. Find the total time that the baking tin is in the oven. Give your answer correct to 3 sig figs.