Discussion
The number of girls is 25 % more than the number of boys in a class. The average height of girls is 156 cm and the average height of boys is 2.5 cm more than the average height of all the boys and girls in the class. What is the average height (in cm) of boys?
Answer: A
The average height of the boys is 160.5 cm. Take 4 boys and 5 girls (girls are 25 % more). Let the boys' average be b, so the class average is b - 2.5. Total height: \[5(156) + 4b = 9(b - 2.5)\] \[780 + 4b = 9b - 22.5\] \[5b = 802.5\] so b = 160.5. Check: the class average is 158, and (780 + 642)/9 = 158. The other options do not satisfy the condition that the boys' average is 2.5 cm above the class average.
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