The 10^-4 means that the decimal point is 4 places to the left of where it is in 8.25 (if the exponent was positive the decimal point would be to the right). If you move the decimal point 4 places to the left you get an answer of 0.000825 which is 8.25 * 10^-4 in standard form.
There are two ways to solve this. The first way is logically. Mary can -wear a pink dress with black shoes -wear a pink dress with white shoes -wear a blue dress with black shoes -wear a blue dress with white shoes -wear a yellow dress with black shoes - wear a yellow dress with white shoes
Count them up, and you'll get six combinations!
Another way is simply mathematically, which is easier in my opinion.
Given : A pelican consumes of its body weight in one meal .
We know that to convert a mixed number into improper fraction , we multiply the denominator of the fraction to the whole number (at left side) and then add the product to the numerator.
i.e.
We know that to convert percentage into fraction , we divide it by 100 .
So ,
Therefore , the required fraction ( in simplest form)=