If the demand for a good increases and simultaneously the su

If the demand for a good increases, and (simultaneously) the supply of the good also increases:

Equilibrium price must decrease, but the effect on equilibrium quantity is uncertain

There must be an increase in both equilibrium price and equilibrium quantity

Equilibrium quantity must decrease, but the effect on equilibrium price is uncertain

Equilibrium quantity must increase, but the effect on equilibrium price is uncertain

Solution

If the demand for a good increases, and (simultaneously) the supply of the good also increases:

Answer

Equilibrium quantity must increase, but the effect on equilibrium price is uncertain.

When supply and demand both increases, we know that the equilibrium quantity will definitely increase. However, because we do not know how much supply and demand will rise respectively, we cannot tell whether the price of the good will increase, decrease, or stay the same.