CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 1
(1) Find the missing variable from a, d, n and
, where a is the first term, d is the common difference and
is the nth term of AP.
(i) a= 7, d = 3, n = 8
(ii) a = -18, n= 10,
(iii) d = -3, n = 18,
(iv) a = -18.9, d = 2.5,
(v) a = 3.5, d = 0, n = 105
Solution (i)
a= 7, d = 3, n = 8
We need to find
here.
Using formula
and putting values of a, d and n, we get
Solution (ii)
a = -18, n= 10,
We need to find d here.
Using formula
and putting values of a,
and n, we get
0 = -18 + (10 – 1)d
Solution (iii)
d = -3, n = 18,
We need to find a here.
Using formula
and putting values of d,
and n, we get
-5 = a + (18-1)(-3)
Solution (iv)
a = -18.9, d = 2.5,
We need to find n here.
Using formula
and putting values of d,
and a, we get
3.6 = -18.9 + (n-1) (2.5)
Solution (v)
a = 3.5, d = 0, n = 105
We need to find
here.
Using formula
and putting values of d, n and a, we get
Leave a Reply