When the price of good A is $50, the quantity demanded of good A is 500 units. When the price of good A rises to $70, the quantity demanded of good A falls to 400 units. Using the midpoint method, O 1. the price elasticity of demand for good A is 0.67, and an increase in price will result in an increase in total revenue for good A O2 the price elasticity of demand for good A is 1.50, and an increase in price will result in a decrease in total revenue for good A. O 3. the price elasticity of demand for good A is 1.50, and an increase in price will result in an increase in total revenue for good A O 4 the price elasticity of demand for good A is 0.67, and an increase in price will result in a decrease in total revenue for good A

The price elasticity of demand for good A is 0.67, and an increase in price will result in a increase in total revenue for good A

Explanation:

The following can be deduced form the question:

P1 = $50

P2 = $70

Q1 = 500 units

Q2 = 400 units

Percentage change in quantity = [Q2 - Q1 / (Q2 + Q1) ÷ 2 ] × 100

Percentage change in price = [P2 - P1 / (P2 + P1) ÷ 2 ] × 100

% change in quantity = (400 - 500)/(400 + 500)/2 × 100

= -100/450 × 100

= -22.22%

% change on price = (70 - 50)/(70 + 50)/2 × 100

= 20/60 × 100

= 33

Price elasticity of demand = % change in quantity / % change on price

= -22.22 / 33

= -0.67

This means that a 1% change in price will lead to a 0.67% change in quantity demanded. As there was a price change, there'll be a little change in quantity demanded because demand is inelastic. Thereby, he increase in price will lead to an increase in the total revenue.

Therefore, the price elasticity of demand for good A is 0.67, and an increase in price will result in an increase in total revenue for good A

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'