Well, we could try adding up odd numbers, and look to see when we reach 400. But I'm hoping to find an easier way.
First of all ... I'm not sure this will help, but let's stop and notice it anyway ...
An odd number of odd numbers (like 1, 3, 5) add up to an odd number, but
an even number of odd numbers (like 1,3,5,7) add up to an even number.
So if the sum is going to be exactly 400, then there will have to be an even
number of items in the set.
Now, let's put down an even number of odd numbers to work with,and see
what we can notice about them:
1, 3, 5, 7, 9, 11, 13, 15 .
Number of items in the set . . . 8
Sum of all the items in the set . . . 64
Hmmm. That's interesting. 64 happens to be the square of 8 .
Do you think that might be all there is to it ?
Let's check it out:
Even-numbered lists of odd numbers:
1, 3 Items = 2, Sum = 4
1, 3, 5, 7 Items = 4, Sum = 16
1, 3, 5, 7, 9, 11 Items = 6, Sum = 36
1, 3, 5, 7, 9, 11, 13, 15 . . Items = 8, Sum = 64 .
Amazing ! The sum is always the square of the number of items in the set !
For a sum of 400 ... which just happens to be the square of 20,
we just need the <em><u>first 20 consecutive odd numbers</u></em>.
I slogged through it on my calculator, and it's true.
I never knew this before. It seems to be something valuable
to keep in my tool-box (and cherish always).
Answer:
14
Step-by-step explanation:
We are given with two 
numbers whose first 
are same.
It is given that their sum is 
adding the last two corresponding digits gives,
Now adding the rest,
to get 
should not give anything to carry as that will make A in decimal to satisfy the addition.
Therefore,
Thus 
And finally,
Thus 
Now simplifying
Thus 
is the answer.
Answer:
if Im correct it should be $8.40
Step-by-step explanation:
why well if you think of breaking down by say 1/4 of 168 all you do is divide 4 which is the whole amount by 0.2 which is the amount the father gave her so 4/0.2= 20 the you take your whole 168 and divide by 20 which the whole number for 0.2 the your answer should be this 168/20= 8.4 which then i assumed it was $8.40 hopefully that is correct hehe
Answer:
968
Step-by-step explanation:
Rectangular Prism: 11*11*5 = 605
Square Pyramid: 11*11 * 9 over 3 = 363
363+605= 968
Answer:
First, you’ll have to collect like terms
4x-x-3x=10+4+5
Next, step is to solve
3x-3x=14+5
0=19
Step-by-step explanation:
I hope the answer to your question is 19, please give me brainliest
