The fourth term of an Ap is 10. If eleventh term is one more three tim

1.	The fourth term of an Ap is 10. If eleventh term is one more three times of the fourth term find the sum of its 25 terms
Answer» Sum of 25 terms = 2000 t 4. =. 10 t 11. =. 3 × 10 + 1 = 31 d. = 31 - 10 / 3 = 7 t 1. = 10 - (2×7) = 10 - 14 =. -4 t 25.= t1 + 24 d = -4 + 168 =. 164 Sn. =. 25 / 2 ( -4 + 164) = (25 × 160 ) / 2. = 2000

The fourth term of an Ap is 10. If eleventh term is one more three times of the fourth term find the sum of its 25 terms

Answer»

Sum of 25 terms = 2000

t 4. =. 10

t 11. =. 3 × 10 + 1

= 31

d. = 31 - 10 / 3

= 7

t 1. = 10 - (2×7)

= 10 - 14

=. -4

t 25.= t1 + 24 d

= -4 + 168

=. 164

Sn. =. 25 / 2 ( -4 + 164)

= (25 × 160 ) / 2.

= 2000