By interchanging the given two signs which of the following equation will NOT be correct?
− and ÷
I. 60 + 20 − 5 ÷ 18 × 3 = 10
II. 40 + 80 ÷ 16 − 9 × 2 = 30
Show answer & explanation
Correct answer: B
Explanation
Interchanging the signs − and ÷ in both equations:
I. 60 + 20 − 5 ÷ 18 × 3 = 10
Interchanging the signs:
60 + 20 ÷ 5 − 18 × 3 = 10
60 + 4 − 18 × 3 = 10
60 + 4 − 54 = 10
64 − 54 = 10
10 = 10 ( correct )
II. 40 + 80 ÷ 16 − 9 × 2 = 30
Interchanging the signs:
40 + 80 − 16 ÷ 9 × 2 = 30
40 + 80 −3.56 = 30
116.44 ≠ 30 ( incorrect )