Gujarati
8. Sequences and Series
easy

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

$7, 15, 19, 21$

Solution

(b) 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 $ ${T_6} = 23 = a + 5d$

$ \Rightarrow $ $d = 4$

Thus ${A_1} = 3 + 4 = 7,\;{A_2} = 7 + 4 = 11,\;$

$A_3 = 11+4 =15 ,\, A_4 = 15+ 4=19$

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.