Solve for the price elasticity of demand for the following goods and then determine if the good is elastic or inelastic. Show your work

a) If the price of sweaters increases by 10%, the quantity demand decreases by 13.5%

b) The original price of yoga pants was $25.00 and 1000 pairs were sold. The price than increased to $30 and the number of pairs sold decreased to 800. Use the midpoint formula