A shop owner has 500 cans of tomatoes that are near their expiration date.She decides to display them in a triangular pyramid and lower the price to try and sell them quickly. How many cans will be on the bottom layer, and will there be any cans left over?

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Answer:

How many cans will be on the bottom layer, and will there be any cans left over?

On the bottom layer will be 31 cans  and there will be 4 cans left over

Step-by-step explanation:

To resolve this problem we need to know Gauss sum of natural numbers, from k = 1 to n:

∑[tex]k=\frac{n*(n+1)}{2}[/tex] (1)

We want to know the value of n when the sum is equal or close to 500, so we replace 500 in the equation (1) to find n:

[tex]500=\frac{n*(n+1)}{2}[/tex]

[tex]500*2=n*(n+1)[/tex]

[tex]1000=n^2+n[/tex]

[tex]n^2+n-1000=0[/tex] (2)

We need to use the quadratic formula to resolve the equation (2)

[tex]n=\frac{-b+/-\sqrt{b^{2} -4ac} }{2a}[/tex] (3)

The coefficients according to equation (2) are:

a=1

b=1

c= 1000

Now, using the quadratic formula we can find n :

Positive sign before the square root,

[tex]n_1=\frac{-1+\sqrt{1^{2} -4(1)(-1000)} }{2(1)}[/tex]

[tex]n_1=\frac{-1+\sqrt{1 + 4000} }{2}[/tex]

[tex]n_1=\frac{-1+63.25}{2}[/tex]

[tex]n_1=\frac{62.25}{2}[/tex]

[tex]n_1=31.13[/tex]

Negative sign before the square root,

[tex]n_2=\frac{-1-\sqrt{1^{2} -4(1)(-1000)} }{2(1)}[/tex]

[tex]n_2=\frac{-1-\sqrt{1 + 4000} }{2}[/tex]

[tex]n_2=\frac{-1-63.25}{2}[/tex]

[tex]n_2=\frac{-64.25}{2}[/tex]

[tex]n_2=-32.13[/tex]

The negative term doesn't have sense in this case, We will use the positive term, the whole number closest to the answer we got when clearing n is 31, we will replace n=31 in the Gauss sum of natural numbers equation. (1)

∑[tex]=\frac{n*(n+1)}{2}[/tex]

∑[tex]=\frac{31*(31+1)}{2}[/tex]

∑[tex]=\frac{31*(32)}{2}[/tex]

∑[tex]=\frac{992}{2}[/tex]

∑[tex]=496[/tex]

Now, we know the triangular pyramid will be 31 cans on the bottom layer and there will be 4 cans left over (500-496=4)