Question

A sum of $8.25 is made up of 100 coins, which are either 10 cents or 5 cents. How many 10 cent coins are there?​

Answer 1

Answer:

65 coins

Step-by-step explanation:

let the number of 10 cents coins be x

let the number of 5 cents coins be y

Now, we know that there are total 100 coins

so, x+y= 100. ---(1)

The total amt of money is 8.25$ i.e. 825 cents

So, 10x + 5y = 825. ---(2)

from equation (1) :

x= 100-y

Using it in eq (2):

10(100-y) + 5y = 825

1000- 10y + 5y = 825

5y = 1000-825

5y= 175

y= 35

Now, x+y= 100

x+35= 100

x = 100-35

x = 65

So, there are 65 coins of 10 cents