Demarco makes miniature mobile generators and has a standard profit margin of 20% for all its products. Its annual budget includes marketing, administration and production overhead allowances of £60,000, £20,000 and £50,000 respectively. It also shows that the company intends to use £18,000 of materials and pay direct wages of £32,000. Marketing and administration overheads are all fixed but 10% of production overheads are considered to be variable. Demarco uses the cost-plus method of setting its selling prices.

Task:
Calculate the cost-plus percentage if the base was:
a) Variable cost;
b) Production cost;
c) Full cost.