## How to Solve Motion Problems Part 3

This is the third part of the How to Solve Motion Problems Series, a part of the Word Problem Solving Series of Ph Civil Service Reviewer. In Part 1 and Part 2 of this series, we discussed objects moving in the same direction. In this part, we are going to discuss objects moving toward each other. We have already discussed four problems in the previous parts of this series, so, we solve the fifth problem.

Problem 5

A car leaves City A and travels towards City B at an average speed of 60 kilometers per hour.  At the same time, another car leaves City B and travels towards city A at an average speed of 70 kilometers per hour. If the two cars use the same route, and if the distance between two cities is 520 kilometers, how many hours before they meet? » Read more

## How to Solve Motion Problems Part 2

This is the second part of the How to Solve Motion Word Problem series. I suggest that you read first the introduction to this series as well as the first part in order to understand better.

In the first part of this series, we discusses about a faster object overtaking a slower one who left first.  In this post, we continue to solve motion problems involving two objects traveling in the same direction and one object faster than the other; this time, they left at the same time. We want to know that given a particular time when they are a number of kilometers apart. » Read more

## How to Solve Motion Problems Part 1

Now that I have introduced to you motion problems, let us solve the type of problems that usually appear in textbooks as well as examinations. In this part of the series, we will learn how to analyze and solve a problem involving objects moving in the same direction. This is our third problem in the How to Solve Motion Problems Series.

Problem 3

Car A left Math City going to English City at an average speed of 40 kilometers per hour.  Two hours later, Car B traveling 60 kilometers per hour leaves the same place for English City. In how many hours, will the car B overtake Car A? » Read more

## Introduction to Motion Problems

We have already finished learning how to solve number problems and age problems, so we continue with learning motion problems. Motion problems deal with moving objects such as cars, planes, boats, etc and their speed, distance traveled and time spent traveling. Walking and running are also usually asked in motion problems. Motion problems also include headwind, tailwind, for planes and other flying objects and upstream and downstream problems on boats traveling in rivers.

Average Speed and Actual Speed » Read more

## The Age Problem Solving Series

One of the common types of word problems in mathematics and in many examinations is about Age Problems. This series discusses various problem styles involving age problems and explains in details how they are solved.

The Age Problem Solving Series

How to Solve Age Problems Part 1 discusses simple 2-person problems particularly present-past and present-future age relationships.

How to Solve Age Problems Part 2 discusses a slightly more difficult 2-person problems particularly present-past and present-future age relationships.

How to Solve Age Problems Part 3 discusses age problems that involves fractions.

I am planning to write a fourth part for this series in the near future, but for now, I will focus more on yet uncovered topics.

## How to Solve Perimeter of Rectangle Word Problems

The perimeter of a polygon is the sum of all the lengths of its sides. Since a rectangle has two pairs of sides, if we call the longer side length and the shorter side width, then

Perimeter = length + length + width + width.

We can shorten this formula if we let $P$ be the perimeter, $l$ be the length and $w$ be the width:

$P = l + l + w + w$

$P = 2l + 2w$.

You see, you don’t have to memorize the formula as long as you know the concept and you know the shape of the polygon. In some of the examples, below, I did not show use the shorter formula since they can be solved intuitively. » Read more

## Introduction to the Concept of Perimeter

Aside from Algebra problems, the Civil Service Examination also contains geometric problems. In this post, I am going to introduce you to the concept of perimeter.

The perimeter of a polygon is the total distance around it. If you have a rectangular pool, for example, and you start walking from one corner along its edge (as near as you can), until you reach the place where you started, then the distance you have walked is its perimeter. » Read more