Answer:

Step-by-step explanation:
We have given that melissa used 4 cups of sugar to bake 54 cookies.
That means 1 cup of sugar will be used to bake
by unitary method
We have to find the ratio of cups to the cookies
We are using 1 cup of sugar
And cookies will be 
End answer is five hundred and 6
Answer:
is scientific notation of 78 billion
Step-by-step explanation:
For scientific notation , follow the following notation:
-------->(equation 1)
Let,
In standard form

or

As decimal point move 10 places from right to left, therefore
b = 10
Put the value of 'a' and 'b' in (equation 1)
is scientific notation of 78 billion
Answer
34 minutes
Step-by-step explanation: