Question 211023:  Sara has a collection of nickels, dimes, and quarters, worth $15.75. She has 10 more dimes than nickels and twice as many quarters as dimes. How many coins of each kind does she have? 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! Sara has a collection of nickels, dimes, and quarters, worth $15.75. She has 10 more dimes than nickels and twice as many quarters as dimes. How many coins of each kind does she have? 
---------------------------------- 
Value Eq.::: 5n + 10d + 25q = 1575 cents 
Quantity Eq: d = n + 10 
Quantity Eq: q = 2d 
--------------------------- 
So n = d-10 
----------------------- 
Substitute in the Value Eq.: 
5(d-10) + 10d + 25*2d = 1575 
5d - 50 + 10d + 50d   = 1575 
65d = 1625 
d = 25 (# of dimes) 
n = d-10 = 15 (# of dimes) 
q = 2d = 50 (# of quarters) 
================================ 
Cheers, 
Stan H.  
  | 
 
  
 
 |   
 
 |