Explanation:
In mathematics, a ratio is a relationship between two
numbers of the same kind (i.e., objects, persons, students, spoonfuls, units of
whatever identical dimension), usually expressed as "a to b" or a:b, sometimes expressed
arithmetically as a dimensionless quotient of the two which explicitly indicates how
many times the first number contains the second (not necessarily an integer).
Notation
and terminology
The ratio of numbers A and B can be expressed as:
1. The
ratio of A to B
2. A is to B
3. A:B
4. A rational number which is the quotient of A divided by B (Our
solved example in mathguru.com uses this concept)
The numbers A and B are sometimes called terms with A being the antecedent and B being the consequent.
http://en.wikipedia.org/wiki/Ratio
Unitary method
The unitary
method is a technique in elementary algebra for solving a class of problems in
variation. It consists of altering one of the variables to a single unit, i.e.
1, and then performing the operation necessary to alter it to the desired
value. (Our solved example in mathguru.com uses this concept)
For example, to solve the problem: A man walks seven miles in two
hours. What is his average speed?' we aim to calculate how far the man walks in
one hour. We can safely assume that he would walk half the distance in half the
time. In one hour (one half of two hours) he walks three and a half miles (one
half of seven miles). His speed is therefore three and a half miles per hour.
We can apply
the same method to the problem 'A man walks at four miles per hour. How long
would it take him to cover five miles?' by asking first, how long does the man
take to walk one mile. One is a quarter of four, so it takes him a quarter of
an hour to walk one mile. To walk five miles it therefore takes him five
quarter hours, or an hour and a quarter.
http://en.wikipedia.org/wiki/Unitary_method
The above explanation is copied from
Wikipedia, the free encyclopedia and is remixed as allowed under the Creative
Commons Attribution- ShareAlike 3.0 Unported License.