A. 10
B. 11.5
C. 12
D. 10.5
Explanation:
Average of the first ‘n’ natural numbers = (n + 1)/2
We get (20 + 1)/2 = 10.5
Related Mcqs:
- The sum of five numbers is 655. The average of the first two numbers is 85 and the third number is 125. Find the average of the two numbers?
A. 180
B. 170
C. 190
D. 175 - The average of 1st 3 of 4 numbers is 16 and of the last 3 are 15. If the sum of the first and the last number is 13. What is the last numbers?
A. 8
B. 6
C. 5
D. 2 - The average of five consecutive odd numbers is 61. What is the difference between the highest and lowest numbers?
A. 2
B. 5
C. 8
D. Cannot be determined - The L.C.M of two numbers is 48. The numbers are in the ratio 2:3. The sum of numbers is__________?
A. 28
B. 32
C. 40
D. 64 - The H.C.F and L.C.M of two numbers are 84 and 21 respectively. If the ratio of the two numbers is 1:4, then the larger of the two numbers is____________?
A. 12
B. 48
C. 84
D. 108 - If the sum of two numbers is 55 and the H.C.F and L.C.M of these numbers are 5 and 120 respectively, then the sum of the reciprocal of the numbers is equal to___________?
A. 55/601
B. 601/55
C. 11/120
D. 120/11 - The average of first 10 natural numbers is____________?
A. 5
B. 5.5
C. 6.5
D. 6 - The average of 13 numbers is 60. Average of the first 7 of them is 57 and that of the last 7 is 61. Find the 8th number?
A. 46
B. 32
C. 68
D. 51 - The average amount with a group of seven numbers is Rs. 20. If the newly joined member has Rs. 50 with him, what was the average amount with the group before his joining the group?
A. Rs. 25
B. Rs. 18
C. Rs. 15
D. Rs. 22 - The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is__________?
A. 25
B. 27
C. 30
D. 35
