3. The school assigned Isabella a task to finish reading a book in one week. In the first three days, she averaged 36 pages per day, and in the next three days, she averaged 44 pages per day, and on the last day, she read the final 10 pages. Therefore, the book has ( ) pages.
(A) 240
(B) 250
(C) 260
(D) 270
(E) 280
3. B.
$$
3 \times 36 + 3 \times 44 + 10 = 250 \text{.}
$$