Question 206294
Jill has $2 in nickels and dimes. She has twice as many nickels as she has dimes. How many nickels and how many dimes does she have? 
This is what I did:
let n represent nickels
let d represent dimes. 
Jill has $2 in nickels and dimes:
5n + 10d = 200 
She has twice as many nickels as she has dimes:
d=2n 
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*** n = 2d, twice as many nickels.
Sub for n into other eqn.
5*2d + 10d = 200
20d = 200
d = 10
n = 20