Simple Ratios problem from old SAT book

[Ognerok]

Homework Statement

Aggregate # of nickels and dimes = 20 coins. If the ratio between nickels and dimes is 2:3, what is cent value of 20-coin set?

Homework Equations

2x = 3y

The Attempt at a Solution

20 = nickels(x)+dimes(y); ratio = 2x:3y; 2x = 3y; y = 2x/3

20 = x + 2x/3; x = 12 nickels; 6 dimes? ...confused from there.

 

[cristo]

Homework Statement

Aggregate # of nickels and dimes = 20 coins. If the ratio between nickels and dimes is 2:3, what is cent value of 20-coin set?

Homework Equations

2x = 3y

The Attempt at a Solution

20 = nickels(x)+dimes(y); ratio = 2x:3y; 2x = 3y; y = 2x/3

20 = x + 2x/3; x = 12 nickels; 6 dimes? ...confused from there.

2x=3y => 24=3y => y=8, not 6!

 

[rock.freak667]

N:D = 2:3
total ratio =5

thus, number of N = 2/5 * 20. I think you can do the rest.