3 nos. in A.P. whose sum is 48

you have a rectangle of of 75 X by16 and you have 4 of those rectangles so multiply 75 X 16 and then multiply the sum by 4
then you have the ends which are squares of 16 X 16 so multiply 16 X 16 Nd then multiply the sum by 2
then add the 2 sums together to get the total square inches of the surface of the object
now one square inch =.00694 square feet so multiply the total sum by .00694 to get the area in square feet
grade 4 maths really

try this :

Instructions

1. Measure the rectangle length, width and height. For example, 8 inches long, 6 inches wide, 10 inches high.
   
2. Multiply the length by the height, then double the product. With this example, 8 inches multiplied by 10 inches results in 80 square inches, which multiplied by 2 equals 160 square inches.
   
3. Multiply the width by the length, then double the product. With this example, 6 inches multiplied by 8 inches equals 48 square inches, which multiplied by 2 equals 96 square inches.
   
4. Multiply the height by the width, then double the product. With this example, 10 inches multiplied by 6 inches results in 60 square inches, which multiplied by 2 equals 120 square inches.
   
5. Sum the amounts from Steps 1 through 3 to find the rectangle surface area. So adding 160, 96 and 120 square inches results in 376 square inches.
   

1 Us gallon is 231 cubic inches

1. Square of a sum
2. Square of a difference
3. Difference of square (also called product of sum and difference)
4. Cube of a sum
5. Cube of a difference
6. Difference of cube
7. Sum of cube

For more information about each type click this link.

This sum is equal to 40+48+56+64+72+...+3024+3032+3040+3048= 40+(48+3048)+(56+3040)+(64+3032)+(72+3024)...
There are (3048-40)/8+1=377 terms in sum. (48+3048)=(56+3040)=(64+3032)=(72+3024)=3096 and there are (377-1)/2=188 pairs whose sum is 3096. Only term that is not in such pair is 40.
Finally sum is 40+188*3096=582088.

4 X 12=48
4 + 12=16
: )

You can calculate the standard deviation as the square root of ((sum of squares - sum^2/n) / (n-1))

To get area, multiply the two sides together.
(4x+3)(4x+3)

16x^2(i.e.squared) + 24x + 9


Proof : If x=2
then side would be 11m
area would be 121m squared

Using our formula,
64 + 48 + 9
or 121m squared

I'm sure there are easier ways to do this but the "brute force" method is to label point A as x1, y1; point b as x2, y2 and point c as x3,y3. Then just do square root of the sum of: (x2-x1)squared+(y2-y1)squared. Save this into memory 'A'. Now do the same for x2,y2 to x3,y3 and add this to the number saved in 'A' and do it once more for x3, y3 to x1, y1 and add to the number in 'A' to get the result.

#include <stdio.h>

int main()
{
int n1, n2, i;
int sum = 0;
n1 = 3;
n2 = 11;

for (i = n1; i <= n2; i++) {
if (i % 2 == 0) {
printf("Adding %d\n", i);
sum = sum + i;
}
}
printf("sum = %d\n", sum);
return 0;
}