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2012 CEMC Gauss (Grade 8) Problems/Problem 5

Revision as of 15:33, 20 April 2025 by Anabel.disher (talk | contribs) (Undo revision 247023 by Anabel.disher (talk))

Problem

How many more coins does it take to make one dollar (100) using only nickels(5 coins) than it takes to make one dollar using only dimes(10 coins)?

$\text{ (A) }\  15\qquad\text{ (B) }\ 10\qquad\text{ (C) }\ 75\qquad\text{ (D) }\ 64\qquad\text{ (E) }\ 54$

Solution

Since a dollar is $100$ cents and a nickel is $5$ cents, there are $\frac{100}{5} = 20$ nickels in a dollar.

Using this logic for dimes and the fact that a dime is $10$ cents, there are $\frac{100}{10} = 10$ dimes in a dollar.

Thus, it takes $20 - 10 = \boxed{\textbf{(B) } 10}$ more coins to make a dollar using only nickels than it takes to make one dollar using only dimes.

~anabel.disher