Question

1 Find 11th term of AP:-5, -5/2.0,5/2,
NCERTEsample
2 fd -- 4, n = 7 and 0,= 4, then find the value of a
CERT Exemplar
3 The first term of an AP is 5, common difference is 3
and the last term is 80. Find the number of terms.
4 Check ifo is a term of the AP:31,28,25, ...
Find p, if the given value of x is the pth term of the
following AP:25, 50, 75, 100, ... : x=1000​

Answer 1

Answer:

3. answer is 26

Step-by-step explanation:

a=5 d=3 an=80 n=?

an=a+(n-1)*d

80=5+(n-1)*3

80=5+3n-3

80=2+3n

80-2=3n

78=3n

n=78/3

n=26