Give the step-by-step reasoning process and then the final answer. Alyssa took 100 photos on vacation. She wants to put them in a photo album with 30 pages. She can place 3 photos each on the first 10 pages. Then she can place 4 photos each on the next 10 pages. If she wants to put an equal number of photos on each of the remaining pages of the album, how many photos can she place on each page?
There are 3 x 10 = 30 photos in total that can be placed in the first 10 pages. There are 4 x 10 = 40 photos in total that can be placed in the next 10 pages. A total of 10 + 10 = 20 pages of the album have been used. A total of 30 + 40 = 70 photos can be placed on those 20 pages. So there are still 100 - 70 = 30 photos left to be placed on the album. And there are 30 - 20 = 10 pages left in the album. Therefore, 30 / 10 = 3 photos can be placed on each of the pages.
The final answer: 3.