I could not understand the solution of "Number system test 12" question number 4

First you need to know. how to find a number of numbers in N!. it is given by N/5 + N/(5^2) + N/(5^3) and so on till each of the term is more than 1 (https://cracku.in/cat/quantitative-aptitude/number-systems/cheatsheet) first we tried randomly for 3000 it has got some 748 zeros and we for every increase in 5.

we get atleast one zero increase. and for every 100 increase the zeros increase atleast by  24. Then they tried for 3300. And then went for 3345. we can find number of zeros are 834 but if we find 3346 zeros it has also same until 3349. but 3350 has more zeros than 834. So 3349 is the maximum number. sum of 3+3+4+9 = 19. hope you got it