Question

Bodhi has a collection of 175 dimes and nickels. The collection is worth $13.30. Which equation can be used to find n, the number of nickels in the collection?

a. 0.1n + 0.05(n – 175) = 13.30
b. 0.1n + 0.05(175 – n) = 13.30
c. 0.1(n – 175) + 0.05 = 13.30
d. 0.1(175 – n) + 0.05n = 13.30

Answer 1

175 is the total number of coins you're using- n represents how many of them are nickles; if you are only using nickles and dimes, what does 175 - n equal?

Answer 2

12?

Answer 3

or to make it easier:
if 175 = total number of nickels and dimes used;
(175 total coins) - (n amount of nickles) = ?

Answer 4

a dime equals $.01 and a nickel equals $.05
so what you want to find is the nickels, so the n would go with the nickels as .05n, but also 175

Answer 5

I don't know if that helps, but what do you think the answer would be

Answer 6

?

Answer 7

Because now you know that it the answer is neither a or b which do you think its going to be?

Answer 8

I think a

Answer 9

No, I meant its either c or d because .5 has to be multiplied by n

Answer 10

also you know that n is going to be smaller than 175 so you would have to subtract n from 175 like this: 175-n
Hope this helps!

Answer 11

is it d?

Answer 12

Yes! Do you understand though?

Answer 13

kind of but still confused. thanks though

Answer 14

No its d because you have to subtract n from 175 like this: 175 - n, as 175 is total amount of coins and your answer would become negative

Answer 15

The answers from Mathematica 9 are attached.
Perhaps you can use those and work backwards.