Kyle has only nickels and dimes in his pocket. If he has 48 coins that total $3.90 how many of each coin does he have ?

Question

I need help ?

Answer 1

let  n = number of nickels, and d= number of dimes

 

then n + d = 48 (the number of coins)

 

then 0.05n + 0.10d = $3.90 (the value of the coins)

 

from equation 1, n = 48 - d

 

substituting into equation 2, we get 0.05(48 - d) + 0.10d = $3.90

which becomes $2.40 - 0.05d + 0.10d = $3.90

solving, d = 30, or $3.00

n = 18, or $0.90