The 3rd term of an Ap is 10 more than the first term while the fifth term is 15more than the second term. Find the sum of the 8th term and 15th term of the AP. If the 7th term is 7times the first term
Let the first term be a and common difference be d.
According to the given conditions:
a + 2d = a + 10 (3rd term is 10 more than first term)
a + 4d = a + 15 (5th term is 15 more than second term)
a + 6d = 7a (7th term is 7 times the first term)
Solving these equations, we get d = 5 and a = -10.
The 8th term is a + 7d = -10 + 7(5) = 25
The 15th term is a + 14d = -10 + 14(5) = 60
Therefore, the sum of the 8th term and 15th term of the AP is 25 + 60 = 85.