SOLUTION: Hello, I am having trouble understanding and solving this problem: Carla has $2.40 in nickels and dimes. Deron has $5.50 in dimes and quarters. Deron has as many dimes as Carla

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Hello, I am having trouble understanding and solving this problem: Carla has $2.40 in nickels and dimes. Deron has $5.50 in dimes and quarters. Deron has as many dimes as Carla       Log On


   

Question 983515: Hello, I am having trouble understanding and solving this problem:
Carla has $2.40 in nickels and dimes. Deron has $5.50 in dimes and quarters. Deron has as many dimes as Carla has nickels and as many quarters as Carla has dimes. How many of each kind of coin does Carla have?

-Thank you.
Found 2 solutions by mananth, josgarithmetic:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Carla has $2.40 in nickels and dimes. Deron has $5.50 in dimes and quarters. Deron has as many dimes as Carla has nickels and as many quarters as Carla has dimes. How many of each kind of coin does Carla have?



Carla has $2.40 in nickels and dimes.
Let Carla have x nickels and y dimes
5x+10y=240..............(1)
Deron has x dimes
Deron has y quarters
10x+25y=550...........(2)
Multiply (1) by 2 and subtract (2)
10x+20y=480
10x+25y=550
-5y= -70
y=14
plug y to get x



Deron has $5.50 in dimes and quarters. Deron has as many dimes as Carla has nickels and as many quarters as Carla has dimes. How many of each kind of coin does Carla have?

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Carla: 0.05%2An%2B0.1d=2.40
The n and d here are for Carla.

Deron: q for how many quarters for Deron.
0.1%2An%2B0.25%2Ad=5.50
Reference must be made to Carla's coin counts according to the written description to form the equation.


Multiply all members by 20.
Carlas: +n%2B2d=48
Deron: 2n%2B5d=110
These variables are FOR CARLA; the counts for Deron are to be checked according to his description.

system%28n%2B2d=48%2C2n%2B5d=110%29

Review the discussion and think, and then continue to solve the system.