Question

Simita has 25 coins, consisting of 10c and 5c, which total $2.25. how many of each does she have?​

Answer 1

Answer:

10c = 20

5c = 5

Step-by-step explanation:

Let x be the number of 10c coins; let y be the number of 5c coins. The total is $2.25, so the amount of 10c and 5c coins will add to that. Simita has 25 coins, so x and y, the number of coins, will have to add to 25. Hence, solve the simultaneous equation.

10x + 5y = 225 (1) - times by 0

x + y = 25 (2) - times by 5

10x + 5y = 225 (1)

5x + 5y = 125 (2)

Then, take equation 2 away from equation 1.

5x = 100

x = 20

Substitute x back into the original equation.

x + y = 25

20 + y = 25

y = 5