# math

1) If the number 1,1/3,1/9, are terms of Geometric progression. Find its common ratio
2) If the second term of Geometric progression is equal to 3, and the 5th term is equal to 81/8. Find the 7th term.
3)If x,y,3 is a Geometric progression. Find the value of x and y
4) Insert 4 numbers between 128 and 4 to form a Geometric progression
5) The average maximum temperature in Cairo town in 1999 was 40 degree C in June, 30 degree C in July, 25.6 degree C in August and it is continue to decrease in the same manner during the following months. what will the average maximum temperature of Cairo be in February 2000 AD {(0.8)to the power of eight 0.168)

1. 👍 0
2. 👎 0
3. 👁 244
1. 1.
r = 2nd/1st or 3rd/2nd
= (1/3) / 1 or (1/9) / (1/3)
= 1/3 for both

2.
ar = 3
ar^4 = 81/8
divide the second equation by the first
r^3 = 27/8
r = 3/2
take it from there

3. to be a GS
y/x = 3/y
y^2 = 3x
that's all you can do, unless you know either x or y

4.
128 , 128r , 128r^2 , 128r^3 , 128r^4 , 4

then 128r/128 = 4/(128r^4)
solve for r

5. you try it, it's easy.

1. 👍 0
2. 👎 0
2. giyfif

1. 👍 0
2. 👎 0
3. The numbers 27;x;y are in geometric progression if the sum of these numbers is 21 calculate the possible value of x and y

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Arithmetic

The sum of three consecutive terms of a geometric progression is 42, and their product is 512. Find the three terms.

2. ### math

5. In a geometric sequence, the sum of the first five terms is 44 and the sum of the next five terms is -11/8. Find the common ratio and first term of the series.

3. ### math

Determine whether each sequence is arithmetic or geometric. Find the next three terms. 1. 14, 19, 24, 29, . . . (1 point) geometric, 34, 39, 44 arithmetic, 32, 36, 41 arithmetic, 34, 39, 44 *** The sequence is neither geometric

4. ### Arithmetic

The first, second and third terms of a geometric progression are 2k+3, k+6 and k, respectively. Given that all the terms of geometric progression are positive, calculate (a) the value of the constant k (b) the sum to infinity of

1. ### algebra

1. The geometric mean between the first two terms in a geometric sequence is 32. If the third term is 4, find the first term. 2. Insert a geometric mean between k and 1/k. 3. If 2 and 3 are two geometric means between m and n,

2. ### MATH

the fist term of a geometric series is 1, the nth term is 128 and the sum of the n term is 225. Find the common ratio and the number of terms?

3. ### Maths

A Geometric progression X has a first term of 4a and its sixth term is 256. Another Geometric progression Y has a first term of 3a and its fifth term is 48. Find the: (i) First term of X (ii) Sum of the first four terms of X

4. ### Can someone help me?!

The 1st, 5th and 13th terms of an arithmetic sequence are the first three terms of a geometric sequence with a common ratio 2. If the 21st term of the arithmetic sequence is 72, calculate the sum of the first 10 terms of the

1. ### mathematics

In a geometric progression with terms, the sum of the first and last term is 66 and the product of the second and second last term is 128. Given that the sum of all the terms of this geometric progression is 126, find the number

2. ### uniuyo

The second and fifth term of a geometric progression are 21 and 567 respectively. Find the first term and the common ratio of the progression

3. ### mathematics

the third terms of a geometric progression is 360 and the sixth term is 1215. find the sum of the first four terms....

4. ### maths

the sum of the 4th and 6th terms of an A.P is 42. the sum of the 3rd and 9th terms of the progression is 52. find the first term, the common difference and the sum of the first ten terms of the progression.