The interior angles of a polygon of n sides are in AP. The smallest angle is 120° and the common difference is 5°. What is the largest interior angle of the polygon ?
160 only
195 only
either 160 or 195
neither 160 nor 195
then which one of the following is correct ?
ln(y) is the GM of ln(x), ln(x), ln(x) and ln(z)
ln(y) is the AM of ln(x), ln(x), ln(x) and ln(z)
ln(y) is the GM of ln(x), ln(x), ln(x) and ln(z)
ln(y) is the AM of ln(x), ln(x), ln(z) and ln(z)
If 3rd, 8th and 13th terms of a GP are p, q and r respectively, then which one of the following is correct ?
q2 = pr
r2 = pq
pqr = 1
2q = p + r
A.
q2 = pr
Given 3rd, 8th and 13th terms of a GP are p, q and r respectively and nth term of a G.P = arn - 1
3rd term = ar2 = p
8th term = ar7 = q
13th term = ar12 = r
Then, from above we can clearly see that : (8th term)2 = (3rd term)(13th term)i.e, q2 = pr
option A is correct.
Let Sn be the sum of the first n terms of an AP. If S2n = 3n + 14n2, then what is the common difference ?
5
6
7
9
Let a, b, c be in AP and k ≠ 0 be a real number. Which of the following are correct ?
1) ka, kb, kc are in AP
2) k –a, k -b, k –c are in AP
3) are in AP
Select the correct answer using the code given below :
1 and 2 only
2 and 3 only
1 and 3 only
1, 2 and 3