Knowee
Questions
Features
Study Tools

The average weight of N boys in a Group is 36 kg.If 20 other boys whose average weight is 30 kg join the the group, the average weight of the group would be the same as what it would be if 5 boys whose average weight is 40 kg leave the group. Find N.a.20b.15c.10d.25

Question

The average weight of N boys in a Group is 36 kg.If 20 other boys whose average weight is 30 kg join the the group, the average weight of the group would be the same as what it would be if 5 boys whose average weight is 40 kg leave the group. Find N.a.20b.15c.10d.25

🧐 Not the exact question you are looking for?Go ask a question

Solution

Let's solve this step by step:

  1. The total weight of N boys is 36N (since average weight = total weight/number of boys).

  2. If 20 boys join the group, the total weight becomes 36N + 20*30.

  3. If 5 boys leave the group, the total weight becomes 36N - 5*40.

  4. According to the problem, these two scenarios result in the same average weight. So, we can set up the following equation:

    (36N + 2030) / (N + 20) = (36N - 540) / (N - 5)

  5. Simplifying this equation gives us:

    36N + 600 = 36N - 200

  6. Solving for N, we find that N = 20.

So, the answer is a. 20.

This problem has been solved

Similar Questions

There are 40 students in a class whose average weight is 56. 25kg.Among these 40 students 25 are boys and 15 are girls. The average weight of 25 boys is 6.8 kg more than the average weight of 15 girls. What is the average weight of 15 girls?

The ratio of the number of boys and girls in a class is 5 : 3. If the average weight of all the boys is 63 kg, whereas that of the girls is 47 kg, find the average weight (in kg) of all the students in the class.

Select the correct answerThe average weight of a certain number of students in a group is 72 kg. If 10 students having an average weight of 78 kg leave and 4 students having an average weight of 80 kg join the group, the average weight of the students in the decreases by 0.7 kg. The number of students initially in the group is?Options46445456

The average weight of 30 students is 45 kg. 15 students whose average weight is 48 kg left the class and 10 students whose average weight is 50 kg joined the class, and then find the new average weight of the students in the class.a45.2b45.4c45.6d45.8

The average weight of a group of 20 boys and calculated to be 89.4 kg and it was later discovered that one weight was misread as 78 kg instead of 87 kg. The correct average weight is?

1/3

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.