Out of four numbers, the average of the first three is 16 and that of the last three is 15. If the last number is 18, the first number is
Solution
Ans.B
The average of first 3 = 16 The average of last 3 = 15 The last number =18 Solution:- Sum of Last 3 numbers= 15*3=45 Hence the last number is 18 So, Sum of 2nd & 3rd = 45-18= 27 Again sum of first three numbers =16*3=48 Therefore the 1st number will be: sum of 1st 3 number-sum of 2nd & 3rd number i.e. 48-27=21
So the answer is 21.
Ans.B
The average of first 3 = 16 The average of last 3 = 15 The last number =18 Solution:- Sum of Last 3 numbers= 15*3=45 Hence the last number is 18 So, Sum of 2nd & 3rd = 45-18= 27 Again sum of first three numbers =16*3=48 Therefore the 1st number will be: sum of 1st 3 number-sum of 2nd & 3rd number i.e. 48-27=21
So the answer is 21.