The sum of 10th and 16th term of an Arithmetic progression is 10 the c

1.	The sum of 10th and 16th term of an Arithmetic progression is 10 the comman difference is -9 Find it's 15th term . a15 =
Answer» ong>ANSWER: - 13 Explanation: Let the first term of the AP is a Then, A/Q, a + 9×(-9) + a + 15×(-9) = 10 Or, 2a - 81 - 135 = 10 Or, 2a = 10 + 81 + 135 Or, 2a = 226 Or, a = 226/2 Or, a = 113 Therefore the 15th term of AP is a + 14D = 113 + 14×(-9) = 113 - 126 = - 13 Ans.

The sum of 10th and 16th term of an Arithmetic progression is 10 the comman difference is -9 Find it's 15th term . a15 =

Answer»

- 13

Explanation:

Let the first term of the AP is a

Then, A/Q,

a + 9×(-9) + a + 15×(-9) = 10

Or, 2a - 81 - 135 = 10

Or, 2a = 10 + 81 + 135

Or, 2a = 226

Or, a = 226/2

Or, a = 113

Therefore the 15th term of AP is

a + 14D

= 113 + 14×(-9)

= 113 - 126

= - 13 Ans.