# Math

posted by .

The sum of the integers from 40 to 60, inclusive, is 1050. what is the sum of the integers from 60 to 80 inclusive?

• Math -

think of an arithmetic sequence where
a=60 and d=1. The sum of the 1st 21 terms is thus

21/2(2*60+20*1) = 1470

or, since each number is 20 more than the terms of the first sequence, add 21*20 = 400, to get 1470

## Similar Questions

1. ### algebra

The sum of the first n counting numbers 1 + 2 + 3 + 4 + 5 ... + n is given by S = n/2(1 + n). a) Find the sum of the numbers 14 to 40 inclusive Answer is 729. But i don't get why. Someone explain what the qestion means by "inclusive" …
2. ### college math

I do not understand a problem from a text book or how to solve the problem for the answer. Could shomeone show me the steps (show work) on how to solve this question. The sum of the intergers from 1 through n is n(n+1)/2. the sum of …
3. ### Math

The sum of the integers from 40 to 60, inclusive, is 1050. what is the sum of the integers from 60 to 80 inclusive?
4. ### Math ( Number Theory )

How many numbers from 1 to 1000 inclusive can be expressed as the sum of k >= 2 consecutive positive integers for some value of k ?
5. ### SAT prep help

Set M consists of the consecutive integers from -15 to y, inclusive. If the sum of all the integers in set M is 70, How many numbers are in the set?
6. ### SAT math

Set M consists of the consecutive integers from -15 to y, inclusive. If the sum of all the integers in set M is 70, How many numbers are in the set?
7. ### Math

The sum of integrs from 40-60, inclusive, is 1050. What is the aum of the integers from 60-80, inclusive?
8. ### Math

the sum of the integers from 1 to 10, inclusive, is 55. What is the sum of the multiples of 5 from 5 to 50 inclusive?
9. ### Math

In an arithmetic series, the sum of the 5th to the 8th terms inclusive is 114, whilst the sum of the 12th to 15th terms inclusive is 198. What is the 21st term?
10. ### Math

Find the sum of all integers between 1200 and 2900, inclusive, which are not divisible by 9.

More Similar Questions