Question 228328
On your way to the movies you grab 50 coins out of the change dish. There are two fewer dimes than twice the number of quarters and two fewer nickels than three times the number of quarters. You have picked up $5.10, just enough for the matinee. What coins do you have?


Step 1.  Let {{{x}}} be the number of quarters.


Step 2.  Let {{{0.25x}}} be the dollar value of quarters.


Step 3.  Let {{{2x-2}}} be the number of dimes since there are two fewer dimes than twice the number of equrters


Step 4.  Let {{{0.10(2x-2)=0.20x-0.20}}} be the dollar value of dimes.


Step 5.  Let {{{3x-2}}} be the number of nickels since there are two fewer nickels than three times the number of quarters


Step 6.  Let {{{0.05(3x-2)=0.15x-0.10}}} be the dollar value of nickels 


Step 7.  Then {{{x+2x-2+3x-2=50}}} since the total number of coins is 50. 


Then, {{{6x-4=50}}} or {{{6x=54}}} so that {{{x=9}}}.


With {{{x=9}}} (quarters), then {{{2x-2=16}}} (dimes) and {{{3x-2=25}}} (nickels).  Note number is 50.  


Now check the dollar value.


{{{9*0.25+16*0.10+25*0.05=2.25+1.60+1.25=5.10}}} which is a true statement.


Step 8.  ANSWER:  The number of quarters is 9, the number of dimes is 16 and the number of nickels is 25.


I hope the above steps were helpful.


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Good luck in your studies!


Respectfully,
Dr J