You have a mixture of 25-cent coins and 50-cent coins.You have 45 coins altogether.The total value of the coins is 18.00 euro. How many of each coin do you have

Question

I am trying to do this but I can't. 

Answer 1

Whenever you have a word problem with a total number of items and a value for each item, you will have two equations:

 

x = number of 25 cent coins

y = number of 50 cent coins

 

Total number of coins equation:  x + y = 45

Total VALUE of coins equation:  0.25x + 0.50y = 18.00

 

Then you solve these two equations by substitution or elimination (linear addition). Does this help?

Answer 2

This type of problem recurs over and over in these questions. The idea is to express the words in terms of equations. Here is a simple example:

Apples sell for 10 cents each; Pears sell for 15 cents each. Betty sold 8 fruits in the past hour and collected 95 cents. How many apples and pears did she sell?

Let A = number of Apples and P = number of Pears. Then you can say that

A + P = 8
and
10A + 15P = 95

Now express A in terms of P in the first equation and substitute in the second equation
A = 8 - P
10(8 - P) + 15P = 95

80 - 10P + 15P = 95
5P = 15
P = 3

Now that you know she sold 3 Pears you can use the fist equation to learn that she sold 5 Applies. Use these numbers in the second equation to prove that the total amount was 95 cents.

10*5 + 3*15 = 95
50 + 45 = 95

You can use the same approach with the coin problem. If you do it yourself you will learn more than if I give you the solution.

 

S = smaller coins

L = larger coins

 

S + L = 45

25S + 50L = 1800