Answer : 95
3895 is a multiple of 5. So the required number, which is the number of people, should end with 5.
The possible answers are 65 , 75 , 85 & 95 ( 13 x 5 ; 15 x 5 ; 17 x 5 ; 19 x 5 )
By mere observation we say that 3895 is divisble by 19 as 19 x 2 = 38 & 19x 5 = 95
95 passengers are on the Bus