Problema Solution

suppose you have a coin collection of dimes and quarters containing 46 coins. If you have $6.70, how many of each type of coin do you have?

Answer provided by our tutors

Let say we have x dimes and y quaters.

All together we have 46 coins.

x+y = 46 ----(1)

 

We have $6.7 from the coins.

One dime cost $0.1 and one quater cost $0.25.

0.1x+0.25y = 6.7

We will multiply the above by 100 to remove the decimals.

10x+25y = 670 -----(2)

 

Now we have to solve (1) and (2) linear equations.

 

(2)-10*(1)

25y-10y = 670-460

 15y = 210

     y = 14

 

From (1) x = 46-14 = 32

 

So we have 32 dimes and 14 quaters.