Correct Answer: 34 and 51, + and ÷

Solution : Given:
19 × 12 – 51 ÷ 34 + 17 = 197

Interchanging the numbers and signs according to the options, to balance the equation –
Let's check the options –
First option: 17 and 51, × and –
⇒19 – 12 × 17 ÷ 34 + 51 = 197
19 – 12 × 0.5 + 51 = 197
19 – 6 + 51 = 197
64 ≠ 197
Second option: 51 and 17, × and ÷
⇒19 ÷ 12 – 17 × 34 + 51 = 197
1.58 – 17 × 34 + 51 = 197
1.58 – 578 + 51 = 197
– 525.42 ≠ 197
Third option: 34 and 51, × and +
⇒19 + 12 – 34 ÷ 51 × 17 = 197
19 + 12 – 0.66 × 17 = 197
19 + 12 – 11.22 = 197
19.78 ≠ 197
Fourth option: 34 and 51,+ and ÷
⇒19 × 12 – 34 + 51 ÷ 17 = 197
19 × 12 – 34 + 3 = 197
228 – 34 + 3 = 197
197 = 197

So, the fourth option satisfies the given equation. Hence, the fourth option is correct.