Question

The four arithmetic means between 3 and 23 are.

• A. 5, 9, 11, 13
• B. 7, 11, 15, 19
• C. 5, 11, 15, 22
• D. 7, 15, 19, 21

Answer 1

Answer: (B)

7, 11, 15, 19

Answer 2

Let four arithmetic means are$A _ { 1 } , A _ { 2 } , A _ { 3 }$and $A _ { 4 }$.

So $3 , A _ { 1 } , A _ { 2 } , A _ { 3 } , A _ { 4 } , 23$

$\Rightarrow$ $T _ { 6 } = 23 = a + 5 d$ $\Rightarrow$ $d = 4$

Thus $A _ { 1 } = 3 + 4 = 7 , A _ { 2 } = 7 + 4 = 11$

$A _ { 3 } = 11 + 4 = 15 , A _ { 4 } = 15 + 4 = 19$