Answer:
Brian's demand is perfectly inelastic.
Crystal's demand is unit elastic.
Step-by-step explanation:
Given that
Brian said = 10 gallons of gas
where, Crystal says = $10 worth of gas
By seeing the above information, we concluded that the Brain's demand is perfectly inelastic as the demand of the gallons are fixed
And, the crystal demand is unitary elastic as the expenditure would remain unchanged or fixed
In addition, the perfectly inelastic is when elasticity is zero , and unitary elastic is when elasticity is equal to one