Question

a piggy bank has $6.95 and contains only nickles and dimes. If there are a total of 91 coins, how many nickles are there

Answer 1

There are 43 nickels in the piggy bank.

Explanation:

Given that:

Number of coins = 91

Worth of coins = $6.95 = 6.95*100 = 695 cents

Let,

x be the number of nickles

y be the number of dimes

According to given statement;

x+y=91 Eqn 1

5x+10y=695 Eqn 2

Multiplying Eqn 1 by 5

5x+5y = 455 Eqn 3

Subtracting Eqn 3 from Eqn 2

(5x+10y)-(5x+5y)=695-455

5x+10y-5x-5y=240

5y = 240

`(5y)/(5)=(240)/(5)`

y = 48

Putting y=48 in Eqn 1

x+48=91

x=91-48

x= 43

Hence,

There are 43 nickels in the piggy bank.