The 3<sup>rd</sup> and 9<sup>th</sup> term of an arithmetic progression are -8 and 10 respective…

How many 2-digit positive integers are divisible by 4 or 9?

If a + 1, 2a + 1, 4a - 1 are in A.P., then the value of a is:

How many terms are there in the GP 5, 20, 80, 320........... 20480?

If the 3<sup>rd</sup> and the 5<sup>th</sup> term of an arithmetic progression are 13 and 21, wh…

The common difference of the A.P. $$\frac{1}{3},$$ $$\frac{{1 - 3b}}{3},$$  $$\frac{{1 - 6b}}{3},$$   …

The sum of third and ninth term of an A.P is 8. Find the sum of the first 11 terms of the progression.

The first and last terms of an A.P. are 1 and 11. If the sum of its terms is 36, then the number of terms will be