Show your work mathematically

Catalina says peanut butter and jelly are perfect complements when used in the fixed proportion of one glob of peanut butter to one glob of jelly. If the current price of a glob of peanut butter is the same as that of a glob of jelly, determine the following: a. The own-price elasticity of demand for peanut butter. b. The cross-price elasticity of a change in the price of jelly on peanut butter con- sumption. c. If the current price of peanut butter is twice the price of jelly, how does this affect the answers in parts (a) and (b)