I need assistance with c, d, & e please.

c. If Walt always buys $50 worth of gas and Jerry always buys 10 gallons worth of gas, what does this tell us about Walt and Jerry's price elasticities of demand for gasoline? d. Suppose that when consumers income rises by 8%, the quantity demanded of cucumbers rises by 3%. What is the price elasticity of demand? Are cucumbers a normal or inferior good? Do they appear to be a necessity or luxury item? e. Suppose that when the price of bread rises by 10%, the quantity demanded of vegemite falls by 4%. What is the cross-price elasticity? -Does it appear that bread and vegemite are related goods? If so, how