Only one member-Shekar- could send an answer which was correct
The answer is that the 8th number is 25
This is arrived at as follows-
The average of the first 2 being 15.5 their total is 31.
The average of the next 3 being 64/3 their total is 64.
The average of all the 8 numbers being 20,their total is 160.
Thus the total of the last 3 should be 160-31-64=65
If the 6th number is denoted by 'x' the 7th and 8th numbers will be (x+4) and (x+7)
So their total will be x+(x+4)+(x+7)=3x+11.
Equating this to 65 we find x,the 6th number is (65-11)/3=18
Hence the 7th and 8th numbers are 22 and 25
The answer is that the 8th number is 25
This is arrived at as follows-
The average of the first 2 being 15.5 their total is 31.
The average of the next 3 being 64/3 their total is 64.
The average of all the 8 numbers being 20,their total is 160.
Thus the total of the last 3 should be 160-31-64=65
If the 6th number is denoted by 'x' the 7th and 8th numbers will be (x+4) and (x+7)
So their total will be x+(x+4)+(x+7)=3x+11.
Equating this to 65 we find x,the 6th number is (65-11)/3=18
Hence the 7th and 8th numbers are 22 and 25
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