Bissoy.com
Doctors Medicines MCQs Q&A

The mean of the 5 smallest numbers from a group is 15 while the mean of all the numbers of the group taken together is 17. If the mean of the numbers leaving the smallest five out is 18.25, how many numbers were there in the group in all?

The mean of the 5 smallest numbers from a group is 15 while the mean of all the numbers of the group taken together is 17. If the mean of the numbers leaving the smallest five out is 18.25, how many numbers were there in the group in all? Correct Answer 13

Let there be x numbers.

Summation of smallest 5 numbers = 5 × 15 = 75

Summation of all the numbers = x × 17

Summation of numbers leaving the smallest five out = (x – 5) × 18.25

Summation of numbers leaving the smallest five out + Summation of smallest 5 numbers = Summation of all the numbers

⇒ (x – 5) × 18.25 + 75 = 17x

⇒ 18.25x – 91.25 + 75 = 17x

⇒ 1.25x = 16.25

∴ x = 13

Related Questions

The mean of the 8 smallest numbers from a group is 17, while the mean of all the numbers of the group taken together is 20. If the mean of the numbers leaving the smallest eight out is 22, how many numbers were present in group in all?
Each of the question below consists of a question and three statements number I, II and III given below it. You have to decide whether the data provided in the statement are sufficient to answer the question. Two person X and Y together can make 25% of total number of bricks in 4.8 days. Another person Z can make 50 bricks in a day. What is the time taken by person X and Z together to make the total number of bricks? I. Dimensions of a brick is (3cm × 4cm × 5cm) while the dimension of a cuboids when all the bricks are put together is (72cm × 80cm × 50cm) and ratio of number of days taken by X and Y alone to make the total number of bricks is 3 : 2. II. The total number of bricks is 4800 and person Y can make 150 bricks in day. III. Total volume of all the bricks together is 1.008m3 and dimension of a bricks is (5cm × 6cm × 7cm) and time taken by Z to make total number of bricks is 200 % more than the total time taken by person Y to make total number of bricks.
City High School must put together a debating team consisting of four debaters.There are candidates of equal ability : X,Y and Z who are all seniors; and A,B,C and D who are all juniors..The school requires that there should be two seniors and two juniors in the team.It is also necessary that all of the debaters be able to work with one another. *Debaters Y and A cannot work together. *Debaters Z and C cannot work together. *Debaters A and B cannot work together. which of the following statements must be false? 1.Debaters Y and C are never selected together. 2.Debaters Z and D are never selected together. 3.Debaters Z and D are never selected together.
In a survey of university students, 64 had taken Drama course, 94 had taken Dance course, 58 had taken a Singing course, 28 had taken Drama and singing course, 26 had taken Drama and dance course, 22 had taken Dance and singing course, and 14 had taken all the three courses. Find how many have taken only one course?
The mean of the 5 smallest numbers from a group is 15 while the mean of all the 13 members of the group taken together is 17. What is the mean of the 8 largest numbers?
The mean of the 6 smallest numbers from a group is 15 while the mean of all the 14 members of the group taken together is 17. What is the mean of the 8 largest numbers?
The mean of the 5 smallest numbers from a group is 18 while the mean of all the 13 members of the group taken together is 20. What is the mean of the 8 largest numbers?
In a survey of 25 students, it was found that 15 had taken Mathematics, 12 had taken Physics and 11 had taken Chemistry, 5 had taken Mathematics and Chemistry, 9 had taken Mathematics and Physics, 4 had taken Physics and Chemistry and 3 had taken all the three subjects. Find the number of students who had taken both Physics and Chemistry but not Mathematics.
A team of five members is to be selected from five boys B1, B2, B3, B4 and B5 and five girls G1, G2, G3, G4 and G5. B2 and G3 have to be selected together. G1 and B5 have to be selected together. B1 and G5 cannot be selected together. G2 and B4 cannot be selected together. G3 and B5 cannot be selected together. Which of the following members may be selected?
A, B, C, D and E play a game of cards. A says to B, "If you give me 3 cards, you will have as many as I have at this moment while if D takes 5 cards from you, he will have as many as E has." A and C together have twice as many cards as E has. B and D together also have the same number of cards as A and C taken together. If together they have 150 cards, how many cards has C got ?