What is the 8th term in the series of `4+8+16+…?

Write down the 4th term in the expansion of (2x^2-1/(4x))^11

The fourth and seventh term of an G.P are 1 and 1/8 respectively.Find the series and the 9th term of the series.

The sixth term and 16th term of an A.P. are —30 and zero respectively. The sum of a particular term with 26th term is the 21th term of the A.P. Determine the term.

The half life of radioactive radon is 3.8 days. What is the time at the end of which 1/20th of the Radon sample will remain undecayed.

Find the 20th term and nth term of the G.P 5/2,5/4,5/8,….

Find the 20th term from the last term of the AP:3,8,13,….243.

Find the 20th term from the last term of the AP:3,8,13,….253.

4th term, 10th term and nth term of an A.P. are 7, 25, 58 respectively. Find 1st term, C.D. and the value of n.

In an A.P. the ratio of 7th term to 11th term is 19 : 31 and the sum of these two terms is 20.Find the sum of first twenty terms.