+0  
 
0
910
3
avatar

If in an AP,ratio of 4th term and 9th term is 1:3 ,find the ratio of 12th and 5th term?

Guest Feb 13, 2016

Best Answer 

 #2
avatar+26969 
+10

Here's a slightly different (but no quicker) way:

 

AP

.

Alan  Feb 13, 2016
 #1
avatar+93289 
+10

If in an AP,ratio of 4th term and 9th term is 1:3 ,find the ratio of 12th and 5th term?

 

\(\frac{a+3d}{a+8d}=\frac{1}{3}\\ 3a+9d=a+8d\\ d=-2a\\~\\ \mbox{Now find }\\ \frac{T_{12}}{T_5}\\ =\frac{a+11d}{a+4d}\\ =\frac{a-22a}{a-8a}\\ =\frac{-21a}{-7a}\\ =3\)

 

So the ratio is 3:1

Ther is probably a quicker way to do this.  ://

Melody  Feb 13, 2016
 #2
avatar+26969 
+10
Best Answer

Here's a slightly different (but no quicker) way:

 

AP

.

Alan  Feb 13, 2016

5 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.