Question

a jar contains nickels and pennies. there are 56 coins in the jar in all. the total value of the coins is 1.52. how many pennies are in the jar

Answer 1

1 penny is just 1c
one nickel is 5 pennies or 5c

alrite...

p = amount of pennies in the jar
n = amount of nickels in the jar

we know there are 56 coins in the jar, thus whatever "p" and "n" are,

p + n = 56

we also know, the total value of all pennies and nickels is one buck and 52 cents, or 1.52.. that's 152 pennies.

now, we know there are 5 pennies in one nickel, so in "n" nickels, there are 5*n pennies, or 5n, thus

p + 5n = 152

$\bf \begin{cases} p+n=56\implies \boxed{n}=56-p\\ p+5n=152\\ ----------\\ p+5\left( \boxed{56-p} \right)=152 \end{cases}$

solve for "p", to see how many penny coins are there.

what about the nickels? well, n = 56 - p.