हिंदी

The product of three numbers in A.P. is 224, and the largest number is 7 times the smallest. Find the numbers

Advertisements
Advertisements

प्रश्न

The product of three numbers in A.P. is 224, and the largest number is 7 times the smallest. Find the numbers

योग
Advertisements

उत्तर

Let the three numbers in A.P. be a – d, a, a + d (d > 0)

Now (a – d) a (a + d) = 224

⇒ a (a2 – d2) = 224  .....(1)

Now, since the largest number is 7 times the smallest

i.e., a + d = 7(a – d)

Therefore, d = `(3"a")/4`

Substituting this value of d in (1), we get

`a(a^2 - (9a^2)/16)` = 224

a = 8

And d = `(3a)/4 = 3/4 xx 8` = 6

Hence, the three numbers are 2, 8, 14.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 9: Sequences and Series - Solved Examples [पृष्ठ १५२]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 9 Sequences and Series
Solved Examples | Q 6 | पृष्ठ १५२

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Find the sum of odd integers from 1 to 2001.


Insert five numbers between 8 and 26 such that the resulting sequence is an A.P.


if `(a^n + b^n)/(a^(n-1) + b^(n-1))` is the A.M. between a and b, then find the value of n.


If the sum of three numbers in A.P., is 24 and their product is 440, find the numbers.


The sum of the first four terms of an A.P. is 56. The sum of the last four terms is 112. If its first term is 11, then find the number of terms.


Show that the following sequence is an A.P. Also find the common difference and write 3 more terms in case.

−1, 1/4, 3/2, 11/4, ...


Show that the following sequence is an A.P. Also find the common difference and write 3 more terms in case. 

9, 7, 5, 3, ...


Which term of the A.P. 4, 9, 14, ... is 254?


Is 68 a term of the A.P. 7, 10, 13, ...?


Which term of the sequence 12 + 8i, 11 + 6i, 10 + 4i, ... is purely imaginary?


How many terms are there in the A.P. 7, 10, 13, ... 43 ?


In a certain A.P. the 24th term is twice the 10th term. Prove that the 72nd term is twice the 34th term.


Find the second term and nth term of an A.P. whose 6th term is 12 and the 8th term is 22.


If < an > is an A.P. such that \[\frac{a_4}{a_7} = \frac{2}{3}, \text { find }\frac{a_6}{a_8}\].


Three numbers are in A.P. If the sum of these numbers be 27 and the product 648, find the numbers.


The sum of three numbers in A.P. is 12 and the sum of their cubes is 288. Find the numbers.


Find the sum of the following arithmetic progression :

50, 46, 42, ... to 10 terms


Find the sum of the following arithmetic progression :

3, 9/2, 6, 15/2, ... to 25 terms


Find the sum of the following arithmetic progression :

 (x − y)2, (x2 + y2), (x + y)2, ... to n terms


Find the sum of the following serie:

 2 + 5 + 8 + ... + 182


Find the sum of all natural numbers between 1 and 100, which are divisible by 2 or 5.


Find the sum of the series:
3 + 5 + 7 + 6 + 9 + 12 + 9 + 13 + 17 + ... to 3n terms.


Solve: 

1 + 4 + 7 + 10 + ... + x = 590.


The sum of first 7 terms of an A.P. is 10 and that of next 7 terms is 17. Find the progression.


If \[\frac{1}{a}, \frac{1}{b}, \frac{1}{c}\] are in A.P., prove that:

a (b +c), b (c + a), c (a +b) are in A.P.


If the sums of n terms of two arithmetic progressions are in the ratio 2n + 5 : 3n + 4, then write the ratio of their m th terms.


Write the sum of first n odd natural numbers.


If the sum of p terms of an A.P. is q and the sum of q terms is p, then the sum of p + q terms will be


If Sn denotes the sum of first n terms of an A.P. < an > such that

\[\frac{S_m}{S_n} = \frac{m^2}{n^2}, \text { then }\frac{a_m}{a_n} =\]

If a1, a2, a3, .... an are in A.P. with common difference d, then the sum of the series sin d [cosec a1cosec a2 + cosec a1 cosec a3 + .... + cosec an − 1 cosec an] is


Mark the correct alternative in the following question:

Let Sn denote the sum of first n terms of an A.P. If S2n = 3Sn, then S3n : Sn is equal to


If second, third and sixth terms of an A.P. are consecutive terms of a G.P., write the common ratio of the G.P. 


If a, b, c are in G.P. and a1/x = b1/y = c1/z, then xyz are in


Find the sum of first 24 terms of the A.P. a1, a2, a3, ... if it is known that a1 + a5 + a10 + a15 + a20 + a24 = 225.


A man saved Rs 66000 in 20 years. In each succeeding year after the first year he saved Rs 200 more than what he saved in the previous year. How much did he save in the first year?


If the sum of n terms of a sequence is quadratic expression then it always represents an A.P


If the ratio of the sum of n terms of two APs is 2n:(n + 1), then the ratio of their 8th terms is ______.


If 100 times the 100th term of an A.P. with non zero common difference equals the 50 times its 50th term, then the 150th term of this A.P. is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×