By interchanging the given two numbers (not digits) which of the following equation will NOT be correct? 2 and 7
I. 7 × 3 + 2 − 6 ÷ 1 = 9
II. 2 × 8 + 7 − 9 ÷ 3 = 40
Show answer & explanation
Correct answer: C
Explanation
I. 7 × 3 + 2 − 6 ÷ 1 = 9
After interchanging 2 and 7:
2 × 3 + 7 − 6 ÷ 1 = 9
6 + 7 − 6 = 9
13 − 6 = 9
7 ≠ 9
II. 2 × 8 + 7 − 9 ÷ 3 = 40
After interchanging 2 and 7:
7 × 8 + 2 − 9 ÷ 3 = 40
56 + 2 − 3 = 40
58 − 3 = 40
55 ≠ 40
Both equations I and II are incorrect.