Sequence And Series Question 297
Question: Let the positive numbers a, b, c, d be in A.P., then abc, abd acd, bcd are
[IIT Screening 2001]
Options:
A) Not in A.P./G.P./H.P.
B) In A.P.
C) In G.P.
D) In H.P.
Show Answer
Answer:
Correct Answer: D
Solution:
$ a,b,c,d $ are in A.P.
Þ $ \frac{a}{abcd},\frac{b}{abcd},\frac{c}{abcd},\frac{d}{abcd} $ are in A.P.
$ \therefore ,\frac{1}{bcd},\frac{1}{acd},\frac{1}{abd},\frac{1}{abc} $ are in A.P.
$ \therefore bcd,acd,abd,abc $ are in H.P.
$ \therefore $ In reverse order abc, $ abd,,acd,,bcd $ are in H.P.
BETA
