A store ordered 300 more than twice as many pens as it did pencils at $5 each. If the cost of a pencil was $4, and the store ordered 15 boxes, each having 80 pencils, calculate the total amount of money they paid for the stationery. Think carefully first, then make a decision:
If the store ordered 15 boxes, each having 80 pencils, they ordered 15 * 80 = 1200 pencils. If the cost of a pencil was $4, the store paid $4 * 1200 = $4800 for all the pencils. Twice as many pens as pencils that the store ordered are 2 * 1200 = 2400. If A store ordered 300 more than twice as many pens as it did pencils, it ordered 2400 + 300 = 2700 pencils. Since the cost of the pens was $5, the store paid 2700 * $5 = $13500 for the pens. The total amount of money they paid for the stationery is 13500 + 4800 = $18300. So, the answer is 18300.