Question

A collection of nickels and dimes is worth 25 dollars. There are twice as many nickels as dimes. How many of each are there? Use let statements and solve algebraically.
May I please get an explanation too?

Answer 1

There are 125 dimes and 250 nickels.

A dime is 0.1$ and a nickel is 0.05$. The total number of them should give 25$.
The number of nickels are twice the number of dimes. So lets call the number of dimes X, then the number of nickels should be 2X.

Putting it in a formula: 0.05(2X) + 0.1X = 25.

Then by solving we get:
0.1X + 0.1X = 25
0.2X = 25
X = 25/0.2 = 125