Answer to the problem of buying promotional items on April 30

It is more economical to buy in both stores in sufficient quantity to receive the promotion than to buy in one store.

Topic:

On the occasion of April 30 - May 1, a group of friends born in the years of Rat, Ox, Tiger, Cat, Dragon, Snake, and Horse planned a picnic in Cua Lo.

Dan was assigned by Suu to go buy drinking water. He went to the food store area and saw that both store A and B were selling 1.5 liter bottles of water for 10,000 VND/bottle.

Store A has a promotion “Buy 5 get 1 free”, which means if you buy 5 bottles you will get 1 bottle for free.

Store B offers a 15% discount to customers who buy 4 or more bottles.

Ask Dan how much money is needed to buy 14 1.5 liter bottles of water?

Prize:

If we buy all 14 bottles at store A, we need to buy 12 bottles and get 2 bottles for free, it will cost 120,000.

If we buy all 14 bottles at store B, we will get a 15% discount and have to pay 14 x 8,500 = 119,000.

However, if we buy 5 bottles at store A, get 1 more bottle for free and buy 8 bottles at store B, the amount to pay will be 50,000 + 8 x 8,500 = 118,000.

It can be proven that it cannot be done better.

The numbers involved in this problem are actually too small to warrant such effort and trouble. However, when working with large numbers, such small details can add up to huge savings.

According to VNE