Question : Directions: Which two signs should be interchanged, to make the given equation correct?
2 ÷ 9 × 18 + 7 – 4 = 1
Option 1: = and ×
Option 2: = and –
Option 3: – and +
Option 4: × and +
Correct Answer: – and +
Solution :
Given:
2 ÷ 9 × 18 + 7 – 4 = 1
Replace the given symbols in the options one by one with the original symbols in the given equation.
First option:
= and ×
2 ÷ 9 × 18 + 7 – 4 = 1
On interchanging the mathematical signs, we get –
2 ÷ 9 = 18 + 7 – 4 × 1
L.H.S. = 2 ÷ 9 = 0.22
R.H.S. = 18 + 7 – 4 × 1
= 18 + 7 – 4
= 18 + 7 – 4
= 0.22 ≠ 21
Second option:
= and –
2 ÷ 9 × 18 + 7 – 4 = 1
On interchanging the mathematical signs, we get –
2 ÷ 9 × 18 + 7 = 4 – 1
L.H.S. = 2 ÷ 9 × 18 + 7
= 4 + 7 = 11
R.H.S. = 4 – 1 = 3
= 11 ≠ 3
Third option:
– and +
2 ÷ 9 × 18 + 7 – 4 = 1
On interchanging the mathematical signs, we get –
2 ÷ 9 × 18 – 7 + 4 = 1
L.H.S. = 2 ÷ 9 × 18 – 7 + 4
= 4 – 7 + 4
= 1
Fourth option:
× and +
2 ÷ 9 × 18 + 7 – 4 = 1
On interchanging the mathematical signs, we get –
2 ÷ 9 + 18 × 7 – 4 = 1
L.H.S. = 2 ÷ 9 + 18 × 7 – 4
= 0.22 + 18 × 7 – 4
= 0.22 + 126 – 4
= 122.22
= 122.22 ≠ 1
Here, only the third option satisfies the R.H.S. of the given equation. Hence, the third option is correct.
Related Questions
Know More about
Staff Selection Commission Multi Tasking ...
Answer Key | Cutoff | Selection Process | Preparation Tips | Eligibility | Application | Exam Pattern
Get Updates Brochure
Your Staff Selection Commission Multi Tasking Staff Exam brochure has been successfully mailed to your registered email id “”.
Upcoming Exams
Trending Articles around SSC MTS
