Sabrina has 2 times more 10 cents than 5 cents in total she has 3.50$ how many 5 cents does she have?

Define x :

Let x be the number of 5 cents she has.
5 cents = x
10 cents = 2x


Find value in term of x :

5 cents = $0.05x
10 cents = 0.10(2x) = 0.2x


Construct Equation :

The total amount is $3.50
⇒ 0.05x + 0.2x = 3.50


Solve x :

0.05x + 0.2x = 3.50
0.25x = 3.5
x = 14


Find the number of coins :

5 cents = x = 14
10 cents = 2x = 2(14) = 28


She has 14 5-cents.