What is the least positive multiple of 25 for which the product of its digits is also a positive multiple of 25?
Lets do it the dumb way
25 - the digit's product is 10, so no.
50 - 0 , so no.
75 - 35, so no.
100 - 0 so no.
125, 150, and 175 and 200 are no because of our past pattern
225 - 20, so no.
250 - 0 so no.
275 - 70 so no.
300 - so no.
325 - 30, so no.
Notice the bolded, every 25 the product of its digits increase by 10.
So,
325 - 30
425 - 40
525 - 50.
525 is answer