economics and business studies

if demand increases, supply extends
if demand decreases,supply contracts
if supply increases, demand extends
if supply decreases, demand contracts

elastic-responsive to a change in market conditions
elasticity-the extent to which buyers and sellers respond to a change in market conditions.
elasticity>responsivness

1.price elasticity of demand when a percentage change in quantity demand respondes to a percentage change in price.

2.income elasticity of demand when a percentage change in quantity demand respondes to a percentage change in income.

3.cross elasticity of demand when a percentage change in quantity demand respondes to a percentage change in price.

4.change in quantity of supply when a percentage change in quantity demand respondes to a percentage change in price.
Formulas:
1) % change QD/% change P=PED
2)% change QD/% change income=YED
3)% change QDA/% change PB=XED
4)% change QS/% change P=SED