What is the smallest integer that is a multiple of 5, 7 and 20 leaving a remainder of 2 in each case

The given problem is a case of geometric progression with the geometric ratio of 3 from the series 1, 3, 9.. the sum is expressed in the equation sum = a1 (1-r^n)/ (1-r), n is equal to 15, a1 is 1 and r is  3.the answer to this series on the first 15 terms is 7174453.