Question

1,3,4,8,15,27,? Find value of question mark

Answer 1

answer is 50
1+3 =4
1+3+4 =8
3+4+8 =15 (leave 1 digit)
4+8+15 =27
8+15+27 =50
so anwer 50

Answer 2

a1=1,a2=3
d=a2-a1
3-1
2
a27=a+(n-1)d
1+(27-1)2
1+(26)2
1+52
53
?=53ans.
hope it helps you.