4+1=5 5+2=12 3+6=21 8+11=?

Given

1+4 =5 and 2+5 =12 and 3+6 = 21,

We need to find 8+11=?

The given sets of addition follows a series of logical thinking

We can notice that

1+4 = 5 ———-(i) as per mathematical techniques

2+5 = 7———-(ii) as per mathematical techniques

Given 2+5=12

Here they have added the result of 1+4 = 5

So 2+5= 7 + 5 =12 ( from (i))

Similarly

3+6 =9 ——-(iii)

3+6= 9 +12= 21 ——- (from (ii)

So

8+11=19 +12 = 40 (from (iii))

Hence

1+4 =5 and 2+5 =12 and 3+6 = 21, then 8+11= 40