Answer
Find out the what fraction of the sandcastle did they build together .
To prove
Let us assume that the fraction of the sandcastle they build together be x .
As given


Than the equation becomes

L.C .M of (3,7) = 21
solving


Therefore the fraction of the sandcastle did they build together be

Hence proved
The length of the molecule is
in scientific notation.
Data;
- Width of molecule = 3*10^-6 cm
- Number of molecules = 225
<h3>Length of the molecule</h3>
This can be calculated as the total length of the 225 molecules added together. To do this, we simply multiply both the numbers of the molecules by the width of the molecule.
This becomes;

The length of the molecule is
in scientific notation.
Learn more on scientific notation here;
brainly.com/question/5756316
brainly.com/question/1712028
Divide common factors from both numerator and denominator.
Divide 2
8/2 = 4
10/2 = 5
8/10 simplified = 4/5
hope this helps
{x+2y+2z=0
{2x+y+z=3
{x-3y-z=1
{x+2y+2z=0
-
{4x+2y+2z=6
{-3x=-6 → x=2
{-3y-z=-1
+
{y+z=-1
{-2y=-2 → y=1
{2+2+2z=0 → 2z=-4 → z=-2
Final triple is
(2; 1; -2)
290-10=280
280 is one standard deviation below.
All that are above mean is 50%.
One standard deviation below is 34%.
50%+34%=84% all of these bags weigh more than 280 g.
So,
100%-84%=16% should be bags that are less than 280 g.
Answer is b) 16 %.