I am lost.

Question: Blake bought 21 books. The least he spent for a book was $18. The most he spent for a book was $25. What could be the amount that he ended up paying for his books?
a.$375
b.$530
c. $175
d. $445

Ahhh, great question!!!!

We know two of the prices, the high and the low, which is a total of $43.
So the average price of the remaining 19 books must be > $18 and < $25

(375-43)/19 = 17.5 no good
(530-43)/19 = 25.6 no good
(175-43)/19 = 6.9 no good
(445-43)/19 = 21.1 YUP!, that's it.

To find the amount that Blake ended up paying for his books, we need to determine the range of possible costs per book. The least amount he spent for a book was $18, and the most he spent was $25.

So, the minimum cost for 21 books would be 21 multiplied by the least amount ($18):

Minimum cost = 21 x $18 = $378

And the maximum cost for 21 books would be 21 multiplied by the highest amount ($25):

Maximum cost = 21 x $25 = $525

Therefore, the amount that Blake ended up paying for his books could be between $378 and $525.

Among the given choices, the closest answer is option d, $445, which falls within the range of possible costs.