Question

1+2=21
2+3=36
3+4=43
4+5=?​

Answer 1

Given:

1 + 2 = 21 , 2 + 3 = 36  and 3 + 4 = 43

We have to find, the value of 4 + 5 = ?​

Solution:

The pattern follow:

Reverse of the digits, Reverse of the digits + $2^{2}$, Reverse of the digits, Reverse of the digits + $2^{2}$, ......

1 + 2 = 1, 2

⇒ Reverse of the digits = 21

2 + 3 = 2, 3

⇒ Reverse of the digits + $2^{2}$ = 32 + 4 = 36

3 + 4 = 3, 4

⇒ Reverse of the digits = 43

Similarly,

4 + 5 = 4, 5

⇒ Reverse of the digits + $2^{2}$ = 54 + 4 = 58

⇒ ? = 58

∴ Missing number (?) = 58

Thus, if 1 + 2 = 21 , 2 + 3 = 36  and 3 + 4 = 43, then "4 + 5 = 58".