mary has $3.50 in change. she has twice as many nickels as quarters. she has one less dime that she has quarters. how many of each coin does she have

Question

i was really confused.....could you show steps?

Answer 1

Hi Julia,

 

My guess is that you are learning to solve word problems using just one variable. So. let's focus on q=#of quarters since quarters is mentioned in relation to both nickels and dimes.

 

q=#of quarters

so the #of nickels = 2q (she has twice as many nickels as quarters)

the #of dimes = q-1 (she has one less dime than quarters)

 

Now it is time to write an equation given the fact that she has $3.50 in change. Let's just do everything in pennies, that is a nickel is 5 pennies, a dime is 10 pennies, a quarter is 25 pennies.

 

That means:

 

25q + 5(2q) + 10 (q-1) = 350 (pennies)

 

25q + 10q + 10q - 10 = 350

 

45q = 360 (added 10 to both sides and combined similar terms)

 q=8  (divide by 45)

n=2(8)=16

d=8-1=7

 

So, 8 quarters, 16 nickels, 7 dimes should give $3.50. Check!