Word Problem Solving Example 1

Question:
In the first day of school, Alison spend two-fifth of her saving. In the second day of school, she spend two-third of her left. If Alison has $10 left in the end of the second school day, how much saving did she has before the school start?
Solution:
We use the variable x to represent the saving she had before the first school day.
In the first school day, she spent (2/5)x and she left x – (2/5)x = (5/5)x - (2/5)x = (3/5)x
In the second school day, she spent (2/3)(3/5)x = (2/5)x and she left (3/5)x – (2/5)x = (1/5)x
Now she has $10 left, we got the equation: (1/5)x = $10
Both sides multiply 5, we got x = $10 (5) = $50
So she had $50 before the first school day.

The problem and solving in this section are for students in grad 6, 7 and 8. Translate word language into a mathematics expression by finding relationship between different objects, write equation based on the relationship and solve equations to find the values of the different objects. This practice can train our brain to obtain the logic thinking skill.