2c+Coin,+travel,+and+investment+mix+problems

To solve coin word problems follow the steps on this website.. http://www.purplemath.com/modules/coinprob.htm Here is an example: Jane bought a pencil and received change for $6 in 20 coins, all nickels and quarters. How many of each kind are given?

First off you need to make a table with quantity and value. Then you need to assign variables for the unknowns. n= # of Nickels. q= # of quarters. Then you fill in you chart and it should look like this. Then you add down each column and you will get. //n + q =// 20 5//n// + 25//q// = 300 Then what you do is use substitution and solve for n of the first equation. So now your equations look like this. //n =// 20 – //q// 5//n// + 25//q// = 300 Then you just sub the first equation in for n in the second equation. 5(20 – //q//) //+// 25//q// = 300 and then just solve normally for q. 5(20 – //q//) //+// 25//q// = 300 100 – 5//q// + 25//q// = 300 25//q// – 5//q// = 300 – 100 20//q// = 200 //q// = 10 Then just plug q back into the first equation of n=20-q n=20-10 n=10 Jane received 10 nickels and 10 quarters
 * || **//quantity//** || **//value//** || **//total//** ||
 * nickels ||  ||   ||   ||
 * quarters ||  ||   ||   ||
 * together ||  ||   ||   ||
 * || **//quantity//** || **//value//** || **//total//** ||
 * nickels || //n// || 5¢ || 5//n// ||
 * quarters || //q// || 25¢ || 25//q// ||
 * together || 20 ||  ||  300 ¢ ||

For solving travel problems visit... http://www.onlinemathlearning.com/rate-time-distance-problems.html Heres an example:

John took a drive to town at an average rate of 40 mph. In the evening, he drove back at 30 mph. If he spent a total of 7 hours traveling, what is the distance traveled by John? Set up a //rtd// table. : Fill in the table with information given in the question. John took a drive to town at an average rate of 40  mph. In the evening, he drove back at  30  mph. If he spent a total of  7  hours traveling, what is the distance traveled by John? Let //t// = time to travel to town. 7 – //t =// time to return from town. Fill in the values for //d// using the formula //d = rt// : Since the distances traveled in both cases are the same, we get the equation:
 * || **//r//** || **//t//** || **//d//** ||
 * Case 1 ||  ||   ||   ||
 * Case 2 ||  ||   ||   ||
 * || **//r//** || **//t//** || **//d//** ||
 * Case 1 || 40 || //t// ||  ||
 * Case 2 || 30 ||  7  – //t// ||   ||
 * || **//r//** || **//t//** || **//d//** ||
 * Case 1 || 40 || //t// || 40//t// ||
 * Case 2 || 30 || 7 – //t// || 30(7 – //t//) ||

40//t// = 30(7 – //t//) Use distributive proe 40//t// = 210 – 30//t// Isolate variable //t// 40//t// + 30//t// = 210 70//t// = 210 The distance traveled by John to town is

40//t// = 120 The distance traveled by John to go back is also 120 So, the total distance traveled by John is 240

The distance traveled by John is 240 miles.

When solving Interest problems use this website.. http://www.onlinemathlearning.com/interest-problems.html

Here is an example: Suppose a bank is offering its customers 3% interest on savings accounts. If a customer deposits $1500 in the account, how much interest does the customer earn in 5 years?

In this problem, we are given the interest rate (**r**), the amount put into the account (**P**), and the amount of time (**t**). However, before we can put these values into our formula, we must change the 3% to a decimal and make it 0.03. Now we are ready to go to the formula. So after 5 years, the account has earned $225 in interest. If we want to find out the total amount in the account, we would need to add the interest to the original amount. In this case, there would be $1725 in the account. Keep in mind that our formula is only for the amount of interest. The formula can also be solved for other variables as in the examples below.