please help!

A person has 20 coins, all nickels and dimes, worth one dollar and 40 cents. How many nickels are there?

If n = number of nickels and d = number of dimes, which system of equations represents the problem?

n + d = 20 and n + d = 1.40
n + d = 20 and 5n + 10d = 1.40
n + d = 20 and 5n + 10d = 140

Question

please help!

A person has 20 coins, all nickels and dimes, worth one dollar and 40 cents. How many nickels are there?

If n = number of nickels and d = number of dimes, which system of equations represents the problem?


n + d = 20 and n + d = 1.40
n + d = 20 and 5n + 10d = 1.40
n + d = 20 and 5n + 10d = 140

jack1 · Answer

n = number of nickles
d = number of dimes

therefore n+ d = 20
so still could be all of them...

nickel is worth 5c
dime is worth 10c
5n + 10d = 140c

so eqn 3 is ur answer

jack1 · Answer

r u right to work out how many nickles from that now? @ttop0816 ?

ttop0816 · Answer

@Jack1  yes!