find the ratio of their 11th terms, Mathematics

The  ratio of the sum of first n terms of two AP's  is 7n+1:4n+27.  Find the ratio of their 11th  terms .

Ans:    Let a1, a2... and d1, d2 be the I terms are Cd's of two AP's.

Sn of one AP    = 7n+1/4n+27

Sn of II AP 

m/2[2a1 +(n-1)d1]/ m/2 [2a2 +(n-1)d2] = 7n+1/4n+27

 

ð  2a1 +(n-1)d1/ 2a2 +(n-1)d2 = 7n+1/4n +27

ð  We have sub n = 21

ð  2a1 +20d1/2a2 +20d2 = 7 x21 + 1/4(21)+27

ð  A1 +10d1/a2 +10d2 = 148 /111

ð  = 4/3

Posted Date: 4/8/2013 6:00:30 AM | Location : United States







Related Discussions:- find the ratio of their 11th terms, Assignment Help, Ask Question on find the ratio of their 11th terms, Get Answer, Expert's Help, find the ratio of their 11th terms Discussions

Write discussion on find the ratio of their 11th terms
Your posts are moderated
Related Questions
can i get some triangle congruence proofs help?

Mean Value Theorem : Suppose f (x) is a function which satisfies both of the following. 1. f ( x )is continuous on the closed interval [a,b]. 2. f ( x ) is differentiable on


Joey participated within a dance-a-thon. His team begin dancing at on Friday 10 A.M. and stopped at 6 P.M. on Saturday. How many hours did Joey's team dance? From 10 A.M. Frida

Functions of Several Variables - Three Dimensional Space In this part we want to go over a few of the basic ideas about functions of much more than one variable. Very first

give me the derivation of external division of sectional formula using vectors


Graphical Method While drawing the graph on a natural scale, the independent variables are marked along the horizontal line and corresponding dependen

what letters to fill in the boxes

Velocity and Acceleration - Three Dimensional Space In this part we need to take a look at the velocity and acceleration of a moving object.    From Calculus I we are famili