What comes next in the series: 1, 4, 10, 19, 31,

here are the possible answers: 36, 48, 46

which answer is the correct one and how to come to that conclusion?

4 - 1 = 3
10 - 4 = 6
19 - 10 = 9
31 - 19 = 12

they are going up by multiples of 3
next is 15

31 + 15 = 46

1, 4, 10, 19, 46

1+3=4
4+6=10
10+9=19
19+12=31
31+15=46
the answer is 46.
(each time adding the next multiple of three)

46. It is the sequence of adding 3,6,9,12,15, etc..

46. The pattern is just adding multiples of 3.