All related (100+)

Explanation 1:

1+4 = 4×1 + 1 = 5

2+5 = 5×2 + 2 = 12

3+6 = 6×3 + 3 =21

The logic here is : Multiply the two digits on left-side and to this product add the first number on the LHS. This gives the number on right-side. Applying this logic to the next two, we write

4+7 = 7×4 + 4 = 28 + 4 = 32

5+8 = 8×5 + 5 = 40 + 5 = 45 (Proved)

Explanation 2:

Given:

1+4 = 5

2+5 = 12

3+6 = 21

If you take differences of numbers on right,

12–5 = 7

21-12 = 9.

This shows that the differences between successive numbers on right-side are in A.P. with common difference = 2. Following this pattern, the next difference will be 11 and consequently the next number on right-side will be 21+11 = 32 and

4+7 = 32.

The next number on right-side will be 32+13 = 45 and

5+8 = 45 (Proved)