Question

Find:
(i) 10th term of the A.P. 1,4,7,10,...
(ii) 18th term of the A.P. $\sqrt{2},3\sqrt{2},5\sqrt{2}$,...
(iii) nth term of the A.P. 13,8,3,-2,...
(iv) 10th term of the A.P. -40,-15,10,35,...
(v) 8th term of the A.P. 117,104,91,78,...
(vi) 11th term of the A.P. 10.0,10.5,11.0,11.5,...
(vii) 9th term of the A.P. $\frac{3}{4},\frac{5}{4},\frac{7}{4},\frac{9}{4}$,...

Answer 1

(i) a=1
d = 4-1= 3
= a + (n-1)d
= 1 + 9(3) =28

(ii) a =
d=
= a + (n-1)d
=+17(2)=35

(iii) a=13
d = 13-8 = 5
= a + (n-1)d
= 13+ (n-1)5 =13+5n-5 = 8+5n

(iv) a= - 40
d = -15 -(-40) = 25
= a + (n-1)d
= - 40+ 9 (25) = 185

(v) a =117
d = 104 - 117= -13
= a + (n-1)d
= 117+ 7(-13) = 26

(vi) a = 10.0
d = 10.5 - 10.0=0.5
= a + (n-1)d
= 10.0 + 10 (0.5) =15.0

(vii) a =
d =
= a + (n-1)d
= + 8 () =