The sum of the digits of the smallest number which, when divided by 18, 21, 25 and 39 leaves a remainder of 3 in each case is:

Correct option is A

Given:

18, 21, 25, 39   

Reminder of 3

Solution: 

If a number leaves the same remainder in multiple cases, subtract the remainder from the number, and find the least common multiple (LCM) of the divisors.

Add the remainder to the LCM to get the smallest number 

=18 = 3$$\times2\times3$$ , 

=21=$$3\times7$$ 

=25= $$5\times5$$ 

=39 = $$3\times13$$

=$$2\times3\times3\times5\times5\times13$$ = 5850

=5850+3 = 5853

= 5+8+5+3 = 21 

Option (a)