Respuesta :

Answer:

10 nickels and 10 quarters

Step-by-step explanation:

Given

Number of coins: 20

Vaiue of coins = $3.00

Required

Number of Nickels and Quarters;

Let N =Nickels and Q =Quarters

The total coins is represented as:

[tex]N + Q = 20[/tex]

1 nickel is equivalent to $0.05 and 1 quarter is equivalent to $0.25; So

[tex]0.05N + 0.25Q = 3[/tex]

Make N the subject of formula in the first equation

[tex]N = 20 - Q[/tex]

Substitute this in the second equation

[tex]0.05(20 - Q) + 0.25Q = 3[/tex]

[tex]1 - 0.05Q + 0.25Q = 3[/tex]

Collect like terms

[tex]-0.05Q + 0.25Q = 3 - 1[/tex]

[tex]0.2Q = 2[/tex]

Multiply both sides by 5

[tex]5 * 0.2Q = 2 * 5[/tex]

[tex]Q = 10[/tex]

Recall that N = 20 - Q

[tex]N = 20 - 10[/tex]

[tex]N = 10[/tex]