price elasticity of demand

If the price elasticity of demand for a product is 2.5, then a price cut from $2.00 to $1.80 will:

a) Increased the quantity demanded by about 2.5 percent

b) Decreased the quantity demanded by about 2.5 percent

c) Increased the quantity demanded by about 25%

d) Increased the quantity demanded by about 250%

Please show working for problem.