Question : Directions: Which two numbers (not digits) should be interchanged to make the following equation correct?
21 × 3 – 10 + 4 ÷ 7 = 5
Option 1: 21 and 4
Option 2: 4 and 7
Option 3: 21 and 3
Option 4: 3 and 7
Don't Miss: Month-wise Current Affairs | Upcoming Government Exams
Correct Answer: 21 and 4
Solution :
Given:
21 × 3 – 10 + 4 ÷ 7 = 5
Interchange the digits according to the given options.
Let's check each option –
First option:
21 and 4
4 × 3 – 10 + 21 ÷ 7 = 5
L.H.S.→4 × 3 – 10 + 3
12 – 10 + 3 = 5
5 = 5
Second option:
4 and 7
21 × 3 – 10 + 7 ÷ 4 = 5
L.H.S.→21 × 3 – 10 + 1.75
63 – 10 + 1.75 = 54.75
54.75
≠ 5
Third option:
21 and 3
3 × 21 – 10 + 4 ÷ 7 = 5
L.H.S.→3 × 21 – 10 + 0.57
63 – 10 + 0.57 = 53.75
53.75
≠ 5
Fourth option:
3 and 7
21 × 7 – 10 + 4 ÷ 3 = 5
L.H.S.→21 × 7 – 10 + 1.33
147 – 10 + 1.33 = 138.33
138.33
≠ 5
So, only the first option satisfies the equation. Hence, the
first 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 “”.
