Discussion
Out of the three given numbers, the first number is twice the second and thrice the third. If the average of the three numbers is 121, what is the difference between the first and the third number ?
Answer: D
The difference is 132.
Let the first number be \(x\). Then the second is \(\frac{x}{2}\) and the third \(\frac{x}{3}\). Their sum is three times the average:
\[ \begin{aligned} x + \tfrac{x}{2} + \tfrac{x}{3} &= \tfrac{11x}{6} = 363 \\ x &= 198,\quad \tfrac{x}{3} = 66 \\ 198 - 66 &= 132 \end{aligned} \]
99 is the second number, and 144 or 77 come from setting up the ratios the wrong way (for example making the second twice the first).
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development