The second term of an arithmetic series is 15, and the fifth is 21. Find common difference, the first term and the sum of the first ten terms.
The fourth term of an arithmetic series is 18, and the common difference is -5. Find the first term and the sum of the first sixteen terms.
Find the difference between the sums of the first ten terms of the arithmetic series. whose first terms are 12 and 8, and whose common differences are respectively 2 and 3.
The first term of an arithmetic series is -12, and the last term is 40. If the sum of the progression is 196, find the number of terms and the common difference.
Find the sum of the odd numbers between 100 and 200.
Find the sum of the even numbers, divisible by three, lying between 400 and 500.
THe twenty-first term of an arithmetic series is 5 1/2 and the sum of the common difference and the sum of the first thirty terms.
Show that the sum of the integers from 1 to n is 1/2n(n+1).
The twenty-first term of an arithmetic series is 37 adn the sum of the first twenty terms is 320. What is the sum of the first ten terms?
An advertisement for an appointment states that the post carries a salary of £1200 p.a. rising by annual increments of £80 to £1760 p.a. What is the total amount that a man would earn if he held the post for 20 years?
Show that the sum of the first n terms of the arithmetic series with first term a and common difference d is 1/2n(2a + (n - 1)d).
Find the sum of the even numbers up to and including 100.
The fifth term of an arithmetic series is 17 and the third term is 11. Find the sum of the first seven terms.
The sum of the second and fourth terms of an arithmetical progression is 15;and the sum of the fifth and sixth terms is 25. Find the first term and the common difference.
The second term of an arithmetical progression is three times the seventh; and the ninth term is 1. Find the first term, the common difference, and which is the first term less than 0
The fourth term of an arithmetical progression is 15, and the sum of the first five term is 55. Find the first term and the common difference, and write down the first five terms.
The sum of the first three terms of an arithmetical progression is 3, and the sum of the first five terms is 20. Find the first five terms of the progression.
How many terms of the arithmetical progression 15 + 13 + 11 + ... are required to make a total of - 367.
The sum of the first six terms of an arithmetical progression is 21, and the seventh terms is three times the sum of the third and fourth. Find the first term and the common difference.
In an arithmetical progression, the sum of the first five terms is 30, and the third term is equal to the sum of the first two. Write down the first five terms of the progression.
The sum of the first n terms of a certain series is n 2 + 5n, for all integral values of n. Find the first three terms and for all integral values of n. Find the first three terms and prove that the series is an arithmetical p progression.
The sum of a number of consecutive terms of an arithmetical progression is -19 1/2, the first term is 16 1/2, and the common difference is -3. Find the number of terms.
In an arithmetical progression, the thirteenth term is 27, and the seventh term is three times the second term. Find the first term, the common difference and the sum of the first ten terms.
What is the smallest number of terms of the geometrical progression, 8 + 24 + 72... that will give a total greater than 6 000 000?