Question

1 + 2 = 21 2 + 3 =36 3 + 4 = 43 4 + 5 =?​

Answer 1

1 + 2 = 21; 2 + 3 =36; 3 + 4 = 43; 4 + 5 = 58

Solution:

As given,

$\bold{1+2 =21 \Rightarrow (reversing \ numbers)}$

$\bold{2+3 = 36 \Rightarrow 32+4 \Rightarrow (reversing \ numbers +4)}$

$\bold{3+4 = 43 \Rightarrow (reversing \ numbers)}$

$\bold{4+5 = (reversing \ numbers +4) = (54+4) = 58}$

Answer 2

The missing number is equal to 58.

Step-by-step explanation:

We have,

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

To find, the value of 4 + 5 = ?

The pattern follow:

Reverse numbers, Reverse numbers + 4, Reverse numbers, Reverse numbers + 4, .....

1 + 2 ⇒ Reverse number 2,1 = 21

2 + 3 ⇒ Reverse number + 4 =  32 + 4 = 36

3 + 4 ⇒ Reverse number 4, 3 = 43

Similarly,

? = 4 + 5 ⇒ Reverse number + 4 =  54 + 4 = 58

∴ The missing number = 58

Thus, the missing number is 58.