# Jamb 2020 Mock Economics expo/Answers

Economics 2019 JAMB Past Questions

Economics 2019 JAMB Past Questions

1. A demand which gives rise to the reverse of the law of demand is__________

A. Derived demand

B. Joint demand

C. Abnormal demand

D. Composite demand

Explanation

A normal demand curve slopes downward from left to right indication. It lower price more will be demand but Abnormal demand curve slopes upward from left to right indications, It higher price more will be demanded which give reverse.

2. If two commodities are unrelated, a change in the price of one will____________

A. have effect on the quantity demanded of the other

B. have no effect on the quantity demanded of the other

C. increase the quantity demanded on the other

D. decrease the quantity demanded on the other

Explanation

The two goods are Independent goods. Therefore, a change in the price of one will have no effect on the other. e.g. refrigerator and bicycle. A change in the price of refrigerator will have no effect on bicycle since they are not related.

3

Price

(₦) Quantity Demanded

8 10

6 12

If we move from 8 to 6, the elasticity of demand is_______

A. -1.25

B. 0.62

C. 1.25

D. 1

Explanation

The elasticity of demand is calculated using:

ρd = % Δ in P

% Δ in Q

Where P = Price

Q = Quantity Demanded

Therefore,

% Δ in P = 6 – 8

8 × 100= -25%

% Δ in Q = 12 – 10

10 × 100= 20%

ρd = -25

20 = -1.25 = 1.25

NOTE: Elasticity of demand is always positive. Therefore, the negative sign is ignored or In extra negative sign is introduced to make it positive. So the answer is 1.25

4. In a perfect competition, the market price is determined by_______

A. the government

B. the producer

C. the consumer

D. the market supply and demand junctions

Explanation

Since the buyers or sellers cannot influence the price of goods and services. The Demand and Supply determined the price the firm can sell any quantity it wishes.

5. In the short-run, the monopoly makes_______

A. Normal profit

B. Abnormal Profit

C. Loss

D. Sales

Explanation

Short-run is a period where some factors are fixed and some are variable.

The short-run monopoly sells OM output at MP (OB) price. The total monopoly profits are AP × CA = CAPB is shaded in the diagram.

CAPB indicates Abnormal profit of the monopolist.

6. The demand curve facing the monopolist in the foreign market is__________

A. Elastic

B. Inelastic

C. Perfectly elastic

D. Unitary

Explanation

The foreign market is perfectly competitive while the home market is monopolistic. Since foreign market is a perfect competitor then the monopolist is faced with average revenue or horizontal demand curve or price line

7. Supply is________

A. A stock

B. A Flow

C. Constant

D. A table

Explanation

Supply is a flow because its relates to a period of time i.e has a time dimension.

8. A rise in the supply of a commodity cause__________

A. an increase in the equilibrium price and decrease in the equilibrium quantity bought and sold

B. an increase in both equilibrium

C. a decrease in the equilibrium price and an increase in the equilibrium quantity bought and sold

D. a decrease in both equilibrium

Explanation

If supply increase while the demand remains constant, there will be an excess supply over demand which will lead to a decrease in the equilibrium price and an increase in equilibrium quantity.

9. The method obtained by adding all the reward of factors of production in national income is________

A. income approach

B. expenditure approach

D. output approach

Explanation

The reward of factors of production are: Rent, Interest, wages & salaries and profit. In national income adding the reward i.e R + I + W + P is used in calculating the income approach.

10. An economy in which the whole income is not consumed is referred to as______

A. Frugal economy

B. Spend thrift economy

C.