Posted by **Malek** on Saturday, January 15, 2011 at 6:45am.

the sum of the 4th term and the 5th term is 12.if the 4th term of the progression is 8, find the common ratio and the 1st term of the progression.

- Math -
**drwls**, Saturday, January 15, 2011 at 7:27am
Call the first term A1.

The An term is A1*r(n-1)

A4 = 8

A4 + A5 = 12 so A5 = 4 and r = 1/2 is the ratio.

Since A4 = 8, A1 = 64 is the first term

The series progression is

64, 32, 16, 8, 4, 2,...

- Math -
**Anonymous**, Tuesday, December 18, 2012 at 2:59am
If 10th term of a G.P. Is 9 and fourth term is 4, then its 7th term is:

## Answer This Question

## Related Questions

- math - the 3rd term of a geometric progression is nine times the 1st term.if the...
- math - The 3rd term of a geometric progression is nine times the 1st term.if the...
- math - if 4th term of an arithmetic progression is 3 times the 1st term nd 7th ...
- math - The 3rd term of a geometric progression is nine times the first term.if ...
- Arithmetic Progression - In an AP the 6th term is half the 4th term and the 3rd ...
- src - the 4th term of an arithmetic progression is 27 and the sum of the 1st and...
- GP Caluculus - The third term of a geometric progression is 16. The sum of the ...
- geometric progression - the 3rd term of a gpis 10 and the 6th term is 80 find ...
- Math Algebra - The first term of a geometric progression is more than the third ...
- GP Caluculus - The third term of a geometric progression is 16. The sum of the ...

More Related Questions