SAT Math Multiple Choice Practice Question 549: Answer and Explanation
6. If it costs z dollars to buy n pizzas, how much will it cost, in dollars, to buy b pizzas at the same rate?
Correct Answer: A
A This is a great problem for Plugging In. Let's try using z = 2, n = 5, and b = 15. If $2 will buy 5 pizzas, then how much will 15 pizzas cost? Three times the number of pizzas will have three times the cost, so $6. Now you just need to figure out which choice will give you $6. Try calculating each of the answer choices, and you'll find that only A equals $6.