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
Mrs. Farrell's class has 26 students. Just 21 were present on Monday. How many were absent? Subtract the number of students present from the total number within the class to de

What is Inductive Reasoning ? Sometimes we draw conclusions based on our observations. If we observe the same results again and again, we conclude that the event always has the

Kurtosis - It is a concept, which refers to the degree of peakedness of a described frequency distribution. The degree is generally measured along with reference to general di

Metallic spheres of radii 6 centimetre, 8 centimetre and 10 centimetres respectively are melted to form a single solid sphere. Find the radius of the resulting sphere.

What is a Function, Anyway? Domain? Range? Next time you're at a fast-food restaurant, take a look at the price list. It may look something like this: • Hamburger.............

Find the number of six-digit positive integers that can be formed using the digits 1,2, 3, 4, and 5 (every of which may be repeated) if the number must start with two even digits o

two circle of radius of 2cm &3cm &diameter of 8cm dram common tangent


72 is 75% what number

how to simplify an expression which has different signs