Given: 19 + 125 ÷ 25 – 100 ÷ 5 + 4 × 3 = 52480÷0.3×5+500190+9×27÷1.6=2480÷0.3×5+500190+9×27÷1.6=2
According to the question, after interchanging the numbers:
Option 1): 19 and 4
19 + 125 ÷ 25 – 100 ÷ 5 + 4 × 3 = 52 ⇒ 4 + 125 ÷ 25 – 100 ÷ 5 + 19 × 3 = 52
⇒ 4 + 125 ÷ 25 – 100 ÷ 5 + 19 × 3 = 52
⇒ 4 + 5 – 20 + 19 × 3 = 52
⇒ 4 + 5 + 57 – 20 = 52
⇒ 66 – 20 = 52
⇒ 46 ≠ 52 (LHS ≠ RHS)
Option 2): 125 and 100
19 + 125 ÷ 25 – 100 ÷ 5 + 4 × 3 = 52 ⇒ 19 + 100 ÷ 25 – 125 ÷ 5 + 4 × 3 = 52
⇒ 19 + 100 ÷ 25 – 125 ÷ 5 + 4 × 3 = 52
⇒ 19 + 4 – 25 + 4 × 3 = 52
⇒ 19 + 4 + 12 – 25 = 52
⇒ 35 – 25 = 52
⇒ 10 ≠ 52 (LHS ≠ RHS)
Option 3): 25 and 5
19 + 125 ÷ 25 – 100 ÷ 5 + 4 × 3 = 52 ⇒ 19 + 125 ÷ 5 – 100 ÷ 25 + 4 × 3 = 52
⇒ 19 + 125 ÷ 5 – 100 ÷ 25 + 4 × 3 = 52
⇒ 19 + 25 – 4 + 4 × 3 = 52
⇒ 19 + 25 + 12 – 4 = 52
⇒ 56 – 4 = 52
⇒ 52 = 52 (LHS = RHS)
Option 4): 4 and 5
19 + 125 ÷ 25 – 100 ÷ 5 + 4 × 3 = 52 ⇒ 19 + 125 ÷ 25 – 100 ÷ 4 + 5 × 3 = 52
⇒ 19 + 125 ÷ 25 – 100 ÷ 4 + 5 × 3 = 52
⇒ 19 + 5 – 25 + 5 × 3 = 52
⇒ 19 + 5 + 15 – 25 = 52
⇒ 39 – 25 = 52
⇒ 14 ≠ 52 (LHS ≠ RHS)
Hence, "Option 3" is the correct answer.