there are three groups of student each contain 25,50and 25student respectively .The average mark that are obtained by the first two groups are 60and 50.the combined average of all the three groups is 58.what is average of the mark the mark that are scored by the third group?
1)62
2)72
3)70
4)65
explain the answer
Answers
Answered by
3
Answer:
2)72
Step-by-step explanation:
Total students = 25+50+25=100
Now,
58=(25*60+50*50+25*x)/100
therefore,
x=72
Answered by
0
The average of the mark the mark that are scored by the third group is 72
let the average mark scored by third group be X
TOTAL STUDENTS IN 3 GROUPS = 25+50+25= 100
TOTAL MARKS SCORED BY ALL STUDENTS = AVERAGE OF COMBINED 3 GROUPS * TOTAL NO. OF STUDENTS IN 3 GROUPS
=58*100
=5800
THEREFORE ACCORDING TO THE QUESTION
25*60 + 50*50 + 25* X = 5800
1500+ 2500+ 25X= 5800
25X= 5800-4000
X= 1800/25
X= 72
SO THE AVERAGE MARKS SCORED BY THE THIRD GROUP IS X= 72
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