If '+' mean '-', '-' means 'x', 'x' means '÷' and '÷' means '+', then value of 16 x 2 ÷ 25 + 7 - 4 is

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 84   14   13 ? 84 ÷ 14 = 6       [rule (i)]
?     6 x 13 = 78     [rule (ii)]
2nd Row 360   24   17 ? 360 ÷ 24 = 15     [rule (v)]
?         15 + 17 = 32     [rule (iii)]
? Resultant difference = 78 - 32 = 46

Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) ? (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 14   5   9 ? 14 + 5 = 19       [rule (ii)]
?     19 x 9 = 171     [rule (i)]
        = w
2nd Row 24   w   88 ? 24   171   88
?         24 + 171 = 195   [rule (ii)]
?       195 - 88 = 107     [rule (v)]
? Resultant of second row = 107

Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) ? (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 73   34   13 ? 73 - 34 = 39       [rule (v)]
?     39 ÷ 13 = 3 = p     [rule (iv)]
2nd Row 32   p   15 ? 32   3   15
?         32 + 3 = 35   [rule (ii)]
?       35 x 15 = 255     [rule (i)]
? Resultant of second row = 525

Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) ? (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 7   21   3 ? 7 x 21 = 147       [rule (i)]
?     147 ÷ 3 = 49 = d     [rule (iv)]
2nd Row d   7   33 ? 49   7   33
?         49 ÷ 7 = 7   [rule (iv)]
?       7 x 33 = 231     [rule (i)]
? Resultant of second row = 231

Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) ? (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 24   64   15 ? 64 - 24 = 40       [rule (iii)]
?     40 + 15 = 55     [rule (ii)]
          = m
2nd Row m   11   15 ? 55   11   15
?         55 ÷ 11 = 5   [rule (iv)]
?       5 x 15 = 75     [rule (i)]
? Resultant of second row = 75

From option (b),
49 - 7 + 3 ÷ 5 x 8 = 24
Change the sign, as per the question,
49 ÷ 7 x 3 - 5 + 8 = 24
? 7 x 3 - 5 + 8 = 24
? 21 - 5 + 8 = 24
? 24 = 24

6 * 4 * 12 * 12
From option (d),
6 x 4 - 12 = 12
? 12 = 12

Using the proper symbols in (c), we get
5 x 2 ÷ 2 < 10 - 4 + 8
? 5 x 1 < 18 - 4 ? 5 < 14
which is true.

Change the proper sign according to question and try all option one by one by applying the BODMAS Rule.
'-' ? ÷
'+' ? '-'
÷ ? 'x'
'x' ? '+'
? 70 ÷ 2 - 4 x 5 + 6 = 21
? 35 - 20 + 6 = 21
? 15 + 6 = 21
? 21 = 21

Using the proper symbols, we have
24 ÷ 12 - 8 + 9
Now Apply the BODMAS Rule,
= 24 x 12 + 18 ÷ 9
= 288 + 2 = 290