Which two signs should be interchanged to make the given equation correct?
20 + 2 ÷ 4 – 8 × 28 = 30

Correct option is B

Given: 20 + 2 ÷ 4 – 8 × 28 = 30
Option (a): Interchange × and –
The modified equation becomes:
20 + 2 ÷ 4 × 8 - 28 = 30
20 + 0.5 × 8 - 28 = 30
20 + 4 - 28 = 30
24 - 28 = 30
-4 ≠ 30 (Not follows)
Option (b): Interchange × and +
The modified equation becomes:
20 × 2 ÷ 4 – 8 + 28 = 30
5 × 2 – 8 + 28 = 30
10 – 8 +28 = 30
38 – 8 = 30
30 = 30 (Follows)
Option (c): Interchange × and ÷
20 + 2 × 4 – 8 ÷ 28 = 30
20 + 2 × 4 – 0.285 = 30
20 + 8 – 0.285 = 30
28 – 0.285 = 30
27.715 ≠ 30 (Not follows)
Option (d): Interchange + and ÷
20 ÷ 2 + 4 – 8 × 28 = 30
10 + 4 – 224 = 30
14 – 224 = 30
-210 ≠ 30 (Not follows)
Thus, correct option is (b).