The average marks of A B and C is 33 and the average marks of B C and D is 37. If A obtains 30 marks, find the marks obtained by D.
Answers
Answered by
50
(A+B+C)/3=33
(30+B+C)/3=33
30+B+C=99
B+C=69 ------------(1)
now,
(B+C+D)/3=37
(69+D)/3=37 [from (1)]
69+D=111
D=42
so, the marks obtained by D are 42.
Answered by
10
Given:
The average marks of A B and C is 33 and the average marks of B, C and D are 37. A obtains 30 marks.
To find:
We have to find the marks of D.
Solution:
The average marks of A B and C are 33.
So, we can write-
A+B+C/3=33
A+B+C=99
A obtains 30 marks.
30+B+C=99
B+C=69
Again the average marks of B, C and D are 37.
So, we can write-
B+C+D/3=37
B+C+D=111
69+D=111
D=111-69
D=42
The mark obtained by D is 42.
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