If price increases by 12 percent and quantity demanded decreases by 10 percent, demand is

a. Jake spends his money on only two things: t-shirts and donuts. Suppose the price of donuts falls. Naturally, Jake buys more donuts. He buys fewer t-shirts. This means that for Jake, the dominates.
b. Becky spends her money on only two things: hiking boots and paintbrushes. For her, the income effect dominates. When the price of paintbrushes rises, Becky will naturally buy fewer paintbrushes. And she will buy hiking boots.

Demand is Inelastic

Jack : Substitution Effect dominates

Becky : Buy fewer hiking boots

Explanation:

Elasticity of Demand is responsive change in demand due to change in price. Demand is : Elastic - When proportionate change (% change) in demand > proportionate (% change) in price and Inelastic - When proportionate change  (% change) in demand < proportionate change (% change) in price .

So, If price rise by 12% & demand decreases by 10% , Demand is Inelastic.

a. Substitution Effect is consumer's shift from dearer to cheaper goods & so,  rise in demand of falling prices good , fall in demand of rising prices good . Jake buying lesser T shirts (relatively expensive) when price of Donuts fall (relatively cheaper) means Substitution Effect dominates for him.

b. Income Effect is price - demand inverse relationship, by change in real purchasing power due to price change. Price rise reduces real purchasing power, decreases demand & price fall increases real purchasing power, increases demand. Becky's paint brush price rise reduces her real purchasing power & she consumes less of both paintbrushes & hiking boots.

answer(d) the growth of consumption is likely to remain sluggish even as the economy begins to recover.;