Fill in the blanks in the following table, given that a is the first term, d the common difference and
the nth term of the AP:

I. Given first term (a) = 7
Common difference (d) = 3
n = 8 ,
an = ?
we know that an = a + (n-1)d
So, we have to find a8
a8 = a + (8-1)d = 7 + 7 × 3 = 28
II.
Given first term (a) = -18
Common difference (d) = ?
n = 10, an = 0
a10 = a + (10-1)d
0 = -18 + 9×d
d = 2
III. Given
Common difference (d) = -3
n = 18, an = -5
first term (a) = ?
a8 = a + (18-1)d
-5 = a + 17×(-3)
a = -46
IV. Given first term (a) = -18.9
Common difference (d) = 2.5
n = ?
an = 3.6
we know that an = a + (n-1)d
3.6 = -18.9 + (n-1)2.5
22.5 = (n-1)2.5
9 = n-1
n = 10
V. Given first term (a) = 3.5
Common difference (d) = 0
n = 105 ,
an = ?
we know that an = a + (n-1)d
an = 3.5 + (105-1)0
an = 3.5
