37   12   21
38   81   14
What is the difference between the resultants of the two rows?

Rules
(i) (2-digit odd number) + (2-digit odd number)
(ii) 2-digit even number ? 2-digit perfect square odd number then, (odd number) - (Even number)
(iii) (3-digit number) ÷ (2-digit number)
(iv) (Prime number) + (Even number)
(v) (Even number) x (Even number)
Solution:
1st Row   23     15     12 ? 23 + 15 = 38
[rule (i)]     ? 38 x 12 = 456     [rule (v)]
2nd Row   X   24   49 ? 456   24   49
? 456 ÷ 24 = 19 [rule (iii)] ? 19 + 49 = 68     [rule (i)]
? Resultant of second row = 68

Divide and add all numbers.
As, 264/2 = 132 ? 1 + 3 + 2 = 6
? 870/3 = 290 ? 2 + 9 + 0 = 11
Similarly, 735/5 = 147 ? 1 + 4 + 7 = 12

Let us check all the options one-by-one.
From option (a),
7 - 4 x 8 x 2 = 24 (using VBODMAS rule)
? 7 - 64 = 24 ? -57 = 24
? LHS ? RHS ? RHS
So, option (a) is incorrect.

From option (b),
7 - 4 x 8 ÷ 2 = 24 (using VBODMAS rule)
? 7 - 4 x 8 ÷ 2 = 24 (using VBODMAS rule)
? 7 - 4 x 4 = 24 ? 7 - 16 = 24
? -9 = 24 ? LHS ? RHS
So, option (b) is incorrect .
From option (c),
7 x 4 - 8 ÷ 2 = 24 (using VBODMAS rule)
? 7 x 4 - 4 = 24 ? 28 - 4 = 24
? 24 = 24 ? LHS = RHS
So, option (c) is correct and hence, there is no need to check option (d).

Here, Right number - Left number = Middle number
As, 43 - 16 = 27, 48 - 36 = 12
similarly, 56 - 29 = 27
? ? = 27

? 40   B   8   T   6   M 3   K   4 = ?
? 40 ÷ 8 - 6 + 3 x 4 = ?
? 5 - 6 + 12 = ?
? 17 - 6 = ?
? ? = 11

Rules
(i) (2-digit odd number) + (2-digit odd number)
(ii) 2-digit even number ? 2-digit perfect square odd number then, (odd number) - (Even number)
(iii) (3-digit number) ÷ (2-digit number)
(iv) (Prime number) + (Even number)
(v) (Even number) x (Even number)
Solution:
1st Row 16   8   32 ? 16 x B = 128     [rule (v)]
?         128 ÷ 32 = 4 [rule (iii)]
                   X
2nd Row 132   11   X² ? 132   11   16
?         132 ÷ 11 = 12 [rule (iii)]
?         12 x 16 = 192 [rule (v)]
? Resultant of second row = 192

Rules
(i) (2-digit odd number) + (2-digit odd number)
(ii) 2-digit even number ? 2-digit perfect square odd number then, (odd number) - (Even number)
(iii) (3-digit number) ÷ (2-digit number)
(iv) (Prime number) + (Even number)
(v) (Even number) x (Even number)
Solution:
2nd Row 45   17   81 ? 45 + 17 = 62     [rule (i)]
?         81 - 62 = 19 [rule (ii)]
1st Row 345   23   X ? 345   23   19
? 345 ÷ 23 = 15 [rule (iii)]
? 345 ÷ 15 + 19 [rule (i)]
? Resultant of first row = 34

Rules
(i) (2-digit odd number) + (2-digit odd number)
(ii) 2-digit even number ? 2-digit perfect square odd number then, (odd number) - (Even number)
(iii) (3-digit number) ÷ (2-digit number)
(iv) (Prime number) + (Even number)
(v) (Even number) x (Even number)
Solution:
1st Row 12   28   84 ? 12 x 28 = 336     [rule (v)]
?         336 ÷ 84 = 4 [rule (iii)]
2nd Row 37   22   18 ? 37 + 22 = 59     [rule (iv)]
?         59 + 18 = 77 [rule (iv)]
? Required sum = 4 + 77 = 81

Rules
(i) (2-digit even number) ÷ ( Even number)
(ii) (Even number) x (Prime number)
(iii) (Odd number) + (Odd number)
(iv) (3-digit number) - (2-digit perfect square number)
(v) (3-digit number) ÷ (2-digit non-perfect square number)
Solution
1st Row 16   7   25 ? 16 x 7 = 112       [rule (ii)]
?     112 - 25 = 87 = m     [rule (iv)]
2nd Row m   23   22 ? 87   23   22
?         87 + 23 = 110   [rule (iii)]
?       110 ÷ 22 = 5     [rule (v)]
? Resultant of second row = 5

Rules
(i) (2-digit even number) ÷ ( Even number)
(ii) (Even number) x (Prime number)
(iii) (Odd number) + (Odd number)
(iv) (3-digit number) - (2-digit perfect square number)
(v) (3-digit number) ÷ (2-digit non-perfect square number)
Solution
1st Row 97   45   71 ? 97 + 45 = 142       [rule (iii)]
?     142 ÷ 71 = 2     [rule (v)]
2nd Row 48   8   11 ? 48 ÷ 8 = 6     [rule (i)]
?         6 x 11 = 66   [rule (ii)]
? Required sum = 2 + 66 = 68