CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 16
16. Determine the AP whose third term is 16 and the 7th term exceeds the 5th term by 12.
Let first term of AP = a
Let common difference of AP = d
It is given that its 3rd term is equal to 16. It means , where is the 3rd term of AP.
Using formula , to find nth term of arithmetic progression, we can say that
It is also given that 7th term exceeds 5th term by12. Again using formula , which is used to find nth term of arithmetic progression, we can say that
According to the given condition, we can say that
Putting (1) in the above equation, we get
Putting value of d in equation , we get
Therefore first term = a = 4
And, common difference = d = 6
Therefore, AP is 4, 10, 16, 22 ....