Which two numbers should be interchanged to make the given equation correct?
66 ÷ 6 + 32 × 4 - 47 = 17

Given: 

66 ÷ 6 + 32 × 4 - 47 = 17

From the given options - 

(a) After Interchanging 47 and 32 we get following equation - 

66 ÷ 6 + 47 × 4 - 32 = 17

11 + 47 × 4 - 32 = 17 

11 + 188 - 32 = 17

199 - 32 = 17

167 $$\not=$$ 17​

(b) After Interchanging 6 and 4 we get following equation - 

66 ÷ 4 + 32 × 6 - 47 = 17

16.5 + 32 × 6 - 47 = 17 

16.5 + 192 - 47 = 17 

208.5 - 47 = 17

​161.5 $$\not=$$​ 17​

(c) After Interchanging 32 and 17 we get following equation - 

66 ÷ 6 + 17 × 4 - 47 = 32 

11 + 17 × 4 - 47 = 32 

11 + 68 - 47 = 32

79 - 47 = 32

Correct answer is (c).​​