Explanation:

Given expression
20 – 8 x 4 ÷ 3 + 2 = ?
After conversion
?= 20 + 8 ÷ 4 – 3 x 2
or, ? = 20 + 2-6
or, ? = 22 – 6=16

Explanation:

Given expression
2 ÷ 6 x 6 ÷ 2 = ?
After changing the signs
? = 2 + 6 ÷ 6 + 2
or, ? = 2 + 1 + 2 = 5

Explanation:

Option (a)

Given expression
6 ÷ 20 x 12 + 7 – 1=70
After conversion
6 – 20 + 12 x 7 ÷ 1=70

Explanation:

Given expression
175- 25 ÷ 5 + 20 x 3 + 10 =?
After conversion
9 = 175 ÷ 25 + 5 x 20 – 3 x 10
or, ? = 7 + 100 – 30 = 77
or, 6 – 20 + 84 = 70
or, 90 – 20 = 70
or, 70 = 70

Explanation:

Option (b)

18 – 3 + 2 x 8 ÷ 6= 14
After conversion
18 ÷ 3 x 2 + 8 – 6 = 14
or, 6 x 2 + 8-6 = 14
or, 12 + 8- 6 = 14

Explanation:

A x C+D means A is the mother of C and C is the father of D Grandchild of A
A+B+D means A is the father of B and B is the father of D. Hence D is the Grandchild of A
D+B+A means D is the father of B and B is the father of A. Here A is the Grand child of D, but we don’t know whether he is the Grandson or Granddaughter of D
A-B-D means A is the son of B and B is the son of D. Hence, A is the Grandson of D

Explanation:

Changing the symbols as given in the problem the above expression is
56÷7+13×11-15×8+2×7

Solving the BODMAS rule, we get 8+143-120+14=165-120=45

Explanation:

Option (d)

38 – 6 × 13 + 66 ÷ 7 = 118
⇒ 38 + 7 × 13 – 66 ÷ 6
⇒ 38 + 91 – 11 ⇒ 118 = 118

Explanation:

Option (b)

20 $ 15 # 10 @ 45 % 15
= 20 + 15 – 10 × 45 ÷ 15
= 20 + 15 – 10 × 3
= 20 + 15 – 30 = 35 – 30 = 5

Solution
36 – 6 + 3 × 5 ÷ 3
→ 36 × 6 ÷ 3 + 5 – 3.
→ 36 × 2 + 5 – 3 = 74.
→ 72 + 5 – 3 = 74