coin equation

[lisamg9657]

Bob has [FONT=MathJax_Main]15[/FONT] coins totaling [FONT=MathJax_Main]$[FONT=MathJax_Main]1.15[/FONT][/FONT]. If he only has dimes and nickels, how many of each coin does he have? I do not know the formula to find the answer.

 

[JeffM]

Bob has [FONT=MathJax_Main]15[/FONT] coins totaling [FONT=MathJax_Main]$[FONT=MathJax_Main]1.15[/FONT][/FONT]. If he only has dimes and nickels, how many of each coin does he have? I do not know the formula to find the answer.

That is because there is no standard formula. You are expected to find the formula for this problem, not memorize one.

Let d = the number of dimes.

Let n = the number of nickels.

First step in ANY word word problem: name the unknowns or variables by assigning letters to each in WRITING.

Second step: translate the relevant facts (either explicitly given in the problem or implicitly assumed) into mathematical statements using the letters assigned in the previous step.

So d + n = 15. Now you find the other relevant fact and translate it into math speak.