Question

the 3 term of a G.P is 360and the 6 term is 1215. find the common ratio and the sum of the first term​ pls I need d answer quickly its urgent

Answer 1

Answer:

First term = 160

Common ratio = 3/2

Step-by-step explanation:

The 3rd term and the 6th term of a G.P are 360 and 1215

The terms are 3 terms apart so find the cube root of the ratio between the 6th and the 3rd term as;

$\frac{1215}{360} =\frac{27}{8} \\\\\sqrt[3]{\frac{27}{8} } =\frac{3}{2} \\\\\\=\frac{3}{2}$

The common ratio is : 3/2

To find the first term, divide the third term by the common ratio to get the second term then do that to the second term to get the first term

360 / 3/2

360 *2/3 = 240  -----2nd term

240/ 3/2

240 * 2/3 = 160 ------1st term