Abuilder buys bricks at the rate of $4.50 per brick for the first 10, $3.50 per brick for the next 10, and $2.50 for any additional bricks. how many bricks can be bought for $100?

If the first 10 bricks come out at $ 4.5, I would be spending $ 45. The other 10 bricks come out at $ 3.5 so he would be spending $ 35. Therefore, he has $ 20 available to buy bricks at $ 2.5, which would be buying 8 additional bricks. Thus, in total, with $ 100, 28 bricks were purchased.

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