Question

Insert three arithmetics means between 4 and 12.

• A. 7,9,11
• B. 6,8,10
• C. 5,8,11
• D. 4,8,12

Answer 1

The correct option is B 6,8,10

We know that when we have to insert "n" arithmetic means between two numbers then the common difference is given by d=(b-a)/(n+1).
The resulting AP is given by a, a+d, a+ (2*d),....a+(n*d) ,b.
Here a=4, b=12, n=3.
Therefore d=(12-4)/(3+1)=2.
The resulting sequence is 4,6,8,10,12
The arithmetic means are 6,8,10.