the mean of A&B is 20. the mean of B&Cis 15.the mean of C&D is 18. find the mean of A&D
Attachments:
Answers
Answered by
2
(A+B) /2 = 20
=> A+B = 40 --------(1)
(B+C)/2 = 15
=> B+C = 30 --------(2)
(C+D) /2 = 18
C+D = 36 -------(3)
On adding equation 1, 2 and 3, we get
A +B +B +C +C + D = 40 + 30 + 36
=> A+D + 2B + 2C = 106
=> A + D + 2(B+C) = 106
=> A+D + 2*30 = 106
=> A +D = 106 - 60
=> A+D = 46
=> A+B = 40 --------(1)
(B+C)/2 = 15
=> B+C = 30 --------(2)
(C+D) /2 = 18
C+D = 36 -------(3)
On adding equation 1, 2 and 3, we get
A +B +B +C +C + D = 40 + 30 + 36
=> A+D + 2B + 2C = 106
=> A + D + 2(B+C) = 106
=> A+D + 2*30 = 106
=> A +D = 106 - 60
=> A+D = 46
Similar questions