Word problem

Question

ABC parking meter accepted 10$ and 20$ notes only when the meter was emptied it was found to contain 380 notes and added up to 6370 how many types of each currency note where there

Answer 1

Let e=number of $10 notes

Let w=number of $20 notes

 

total number of notes =T=e+w=380

 

6370=total value of $10 notes+total value of $20 notes=10e+20w

 

system of equations

e+w=380

10e+20w=6370

 

substitution

w=380-e

10e+20(380-e)=6370

10e+7600-20e=6370

-10e=-1230

e=123

123+w=380

w=257

 

123 ten dollar bills and 257 twenty dollar bills