Ruby has $0.86 worth of pennies and nickels. She has 4 more nickels than pennies. Determine the number of pennies and the number of nickels that Ruby has.

Step-by-step explanation:

The worth of a penny is 1 cent. Converting to dollars, it becomes

1/100 = $0.01

The worth of a nickel is 5 cents. Converting to dollars, it becomes

5/100 = $0.05

Let x represent the number of pemnies that Ruby has.

Let y represent the number of nickels that Ruby has.

She has 4 more nickels than pennies. This means that

y = x + 4

Ruby has $0.86 worth of pennies and nickels. This means that

0.01x + 0.05y = 0.86 - - - - - - - - - - - 1

Substituting y = x + 4 into equation 1, it becomes

0.01x + 0.05(x + 4) = 0.86

0.01x + 0.05x + 0.2 = 0.86

0.06x = 0.86 - 0.2 = 0.66

x = 0.66/0.06

x = 11

y = x + 4 = 11 + 4

y = 15

#12 the answer is the third option