Correct Answer: ÷ and +, 5 and 7

Solution : Given:
84 + 5 × 4 ÷ 32 – 7 = 75

Let's check the options –
First option: + and ×, 84 and 32
= 32 × 5 + 4 ÷ 84 – 7
= 32 × 5 + 0.0476 – 7
= 160 + 0.0476 – 7
= 153.0476 ≠ 75
Second option: – and ÷, 4 and 7
= 84 + 5 × 7 – 32 ÷ 4
= 84 + 5 × 7 – 8
= 84 + 35 – 8
= 111 ≠ 75
Third option: ÷ and +, 5 and 7
= 84 ÷ 7 × 4 + 32 – 5
= 84 ÷ 7 × 4 + 32 – 5
= 12 × 4 + 32 – 5
= 48 + 32 – 5
= 75 = R.H.S.
Fourth option: + and –, 5 and 4
= 84 – 4 × 5 ÷ 32 + 7
= 84 – 4 × 5 ÷ 32 + 7
= 84 – 4 × 0.15625 + 7
= 84 – 0.625 + 7
= 90.375 ≠ 75

So, only the third option satisfies the equation. Hence, the third option is correct.