We are given that there 2102 copies of a brochure, and that this brochure contains 5 photos. We are asked how many times do these photos appear in the brochures.
To find the number of times all 5 photos will appear in all of the printed brochures we need to multiply the number of photos by the number of printed brochures, that is:
therefore, the 5 photos will appear 10510 times. We know it's reasonable because there are 5 photos per brochure, therefore, the total number of photos must be the product of the number of photos per brochure by the total number of brochures.