The sum of the first n odd numbers is n squared! So, the short answer is that the sum of the first 70 odd numbers is 70 squared, i.e. 4900.
Allow me to prove the result: odd numbers come in the form 2n-1, because 2n is always even, and the number immediately before an even number is always odd.
So, if we sum the first N odd numbers, we have

The first sum is the sum of all integers from 1 to N, which is N(N+1)/2. We want twice this sum, so we have

The second sum is simply the sum of N ones:

So, the final result is

which ends the proof.
The greatest possible number of club members is 7
<em><u>Solution:</u></em>
Given that, local readers’ club has a set of 49 hardback books and a set of 21 paperbacks
Each set can be divided equally among the club members
To find the greatest possible number of club members, we have to find the greatest common factor of 49 and 21
The greatest number that is a factor of two (or more) other numbers.
When we find all the factors of two or more numbers, and some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.
<em><u>Greatest common factor of 49 and 21:</u></em>
The factors of 21 are: 1, 3, 7, 21
The factors of 49 are: 1, 7, 49
Then the greatest common factor is 7
Thus, the greatest possible number of club members is 7
Answer:
Step-by-step explanation:
I always like to use the mean if I can. In this data set, it's probably not a very good idea. Too much weight is given to that 7.2 and the two 3.2s.
I would choose the median, because the mode is the same answer and that's a good enough reason for choosing anything. 2 out 3 isn't bad as they say in Baseball.
Answer:Exponential
Step-by-step explanation:
Y= .5x.2^x
Answer:
$84.14
Step-by-step explanation:
Begin by multiplying 1.035 by 4.
Get 4.14.
Add this to the original amount deposited, $80.
The answer is $84.14