The third, fourth and fifth term of a geometric progression are t+3, t+8 and t+18. find the common ratio, first term and the sum of the first twelve terms.

In geometric progressions, the ratio between consecutive terms is constant. This implies that

Solve this equation and you'll find the solution t=2.

So, the 3rd, 4th and 5th terms are (plug t=2 in the given terms)

So, the series goes on multiplying terms by 5, and it is

The sum of the first 12 terms is:

l.jnl.j/n.m,lm,

step-by-step explanation: