12 The mean time for running a race by a group of 20 people was 54 seconds. The times for a second group of people were added and the value of the mean went up to 56 seconds. Which formula represents the relationship between the number of people in the second group, P. and the mean time of the second group, T? 40 A P= T -54 1080 B P = T -54 40 C P= T -56 1080 D P= T -56 1120 E P = . 20 T2D The total surface area at a cylinder is numerically the same as its volume. The radius of the cylinder is rem1 the height is h cm. Express h in terms at r. A 19:1 12 B h: 2? 1+2 C =r+2 D zrE \f