in an ap sixth term is 1 more than twice the third term the sum of the 4 and 5 term is 5times the second term find 10th term if the ap
Answers
Answered by
5
★Given :
- In an Arithmetic Progression sixth term is one more than twice the third term.
- The sum of the fourth and fifth terms is five times the second term.
★To find :
- The tenth term of the Arithmetic Progression.
★Solution:
Let the AP is,
→a , a + d , a + 2d...
Where,
- a = first term
- d = common difference
Then,
- Second term = a + d
- Third term = a + 2d
- Sixth term = a + 5d
- Fourth term = a + 3d
- Fifth term = a + 4d
Given that sixth term is one more than twice the third term.Therefore,
Sixth term = third term + 1
➜a + 5d = 2(a + 2d) + 1
➜a + 5d = 2a + 4d + 1
➜a-2a+5d-4d = 1
➜ d - a = 1
➜d = a + 1-------(1)
Given,sum of the fourth and fifth terms is five times the second term.
Fourth term + fifth term = 5(second term)
➜(a + 3d) + (a + 4d) = 5(a + d)
➜2a + 7d = 5a + 5d
➜2d = 3a
➜2(a + 1) = 3a
➜2a + 2 = 3a
➜ a = 2
Now substituting the value of 'a' in equation(1),
➜d = a + 1
➜2 + 1 = 3
Therefore,the common difference is 3.
Now,
➜10th term = a + 9d
➜2 + 9(3)
➜29
Hence,10th term of AP is 29.
____________
Similar questions