Answer:
-10%
Step-by-step explanation:
price elasticity of demand = % change in demand / % change in price
Here, the "price" changes from 15 to 45, so its percent change is ...
((new value)/(old value) -1) × 100%
= (45/15 -1) × 100%
= 200%
The % change in demand is given as -20%, so the price elasticity is ...
price elasticity of demand = (-20%)/(200%) = -0.10 = -10%
