Answer in decimal form: 37.69911184
Answer:
Step-by-step explanation:
in one hour if i am correct they will pave 0.928 or 0.930 miles
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).
120 : 8 = 15
and 15 x 20 = 300, so the answer is C
Answer:
15, 22, 88
Step-by-step explanation:
I assume you mean the second number is 7 more than the first. Write the system of equations:
x + y + z = 125
y = x + 7
z = 4y
Substitute the third equation into the first.
x + y + 4y = 125
x + 5y = 125
Substitute the second equation.
x + 5(x + 7) = 125
6x + 35 = 125
6x = 90
x = 15
Solve for the other variables.
y = 22
z = 88
