Q1) (Fill in the black and show working out):

There is a road named High Street with 1000m long. There are two grocery shops: Woolworths located at the left end and Coles located at the right end. 3000 customers are uniformly distributed along High Street. To make our life easier, assume both grocery stores sell the same product, and consumers demand just one unit of the product. Traveling to a grocery shop is costly, and the cost of traveling is 3 cents per meter. Suppose the price of the product is $15 at Woolworths, and $12 at Coles. Then ____________ customers will purchase the product from Woolworths.