If Sergio has 4 times as many nickels as quarters and they have a combined value of 315 cents, how many of each coin does he have?

Answer 1

Look TD,

You know right off that the value is going to be the "deal-breaker", right?

But, you have to put together some number of the coins to get that.

To do this painessly, look for the item that will be least in number -- here, that's the quarters, since there are 4x that number of nickels. Why did I do this? So that I can deal in 4Q, as opposed to in (1/4)Q, as a variable for the "other" coin. Avoid fractions if you can, possibility for errors!

So then: Q = number of quarters. The NUMBER of nickels is then 4Q.

So let's tote up value. Nickels = 4Q*5 (as cents) ; Quarters = Q*25 (as cents).Or totaling: 20Q+25Q=45Q=315

Q=7 quarters , 4Q=28 nickels

By the way, Sergio is asking for a ripped out pocket if he carries all that. 12 quarters and 3 nickels would weigh quite a bit less, I think.

-- Cheers, --Mr. d.