7. Find the sum of the first 8 terms of the geometric series with the first term 8 and the second term is 24.

8. Find the 30th term of the harmonic sequence if its 1st term is ½ and the common difference is ¼

9-10. Mr. Reyes saves 100 pesos in January then saves thrice as much as the previous month. How much does he save after 6 months?​