50% since you have a half chance of getting 1 to 4 and other half is 4-8
To work out the area of a semicircle<span> you can use the formula A = (Pi*r^2)/2. This is because the </span>area<span> of a full</span>circle<span> is A = Pi*r^2 and a </span>semicircle<span> is </span>half<span> the </span>area<span> of a full</span>circle<span> so you divide this by 2. Just be careful to substitute the radius into the formula and not the diameter!
</span>
Many numbers, when multiplied by
, are less than
. We can find an inequality for numbers
that are sufficient.
Clearly,
is the desired inequality. We divide by 7 to find that
determines working numbers.
The shadow is the square to the two equal parts
