Question

HHHHHEEEELLLPPPPPPPP!!!!!!!!!!!!!!!!!!

A purse contains 21 coins consisting of nickels and dimes. Find the number of coins of each kind if the total value is $1.65.

If 5n represents the value of the nickels, then which of the following expressions represents the value of the dimes?


10n
16n
10(21 - n)

Answer 1

a nickel is 5cents
a dime is 10cents, that is, twice as much of a nickel, or 2 nickels, or 2*nickels

if a nickel = 5n then a dime is 2 * 5n
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we know the purse has 21 coins, with only nickels and dimes
say the quantity of nickels is "n"
and the quantity of dimes is "d"

so we could say that ---> n + d = 21
all nickels plus all dimes, add up to 21 coins

total value of all is $1.65

we know that a nickel is 5cents
and a dime is 10cents
we also know that $1.65 is 165 cents


(5 * quantity of nickels) + (10 + quantity of dimes) = 165

5n + 10d = 165

but a "d = 2n", twice as much as nickel

5n + (2n) = 165


# solve for "n" to find out how many nickel coins are there

the remainder, will be dimes

Answer 2

hmmm

Answer 3

5n + 10d = 165

but a "d = 2n", twice as much as nickel

5n + 10(2n) = 165

Answer 4

lemme double-check that

Answer 5

we know .... that all nickels and dimes add up to 21 coins and $165 pennies
so
\(\bf n+\color{red}{d}=21\\ \quad \\
5n+10\color{red}{d} = 165\\ \quad \\ \quad \\
n+\color{red}{d}=21\implies d = \color{red}{21-n}\\ \quad \\
\textit{so we could say that}\\
5n+10d = 165\implies 5n+10(\color{red}{21-n}) = 165\)

solve for "n" to find out how many nickels there are
the remaining change, is dimes :)

Answer 6

thankx that helped...........