Question

A person has 22 coins, all nickels and dimes, worth one dollar and 40 cents. If n is the number of nickels and d is the number of dimes, which system of equations could represent this problem?

n+d=1.40
0.05n+0.1d=22

n+d=22
n+d=1.40

n+d=22
0.05n+0.10d=1.40

Answer 1

the third one

Explanation:

Answer 2

The third system, because your total amount of coins (n+d) is 22 coins. Since a nickel is worth $0.05, and a dime is worth $0.10, you multiply n by 0.05, and multiply d by 0.10 to get the financial value of the coins in dollars.