SOLUTION: Hanna has $11.20 in a jar that contains only nickels and dimes. There are 140 coins in the jar. How many dimes are in Hanna's jar?

Question 558028: Hanna has $11.20 in a jar that contains only nickels and dimes. There are 140 coins in the jar. How many dimes are in Hanna's jar?
Answer by saifoo.khan(162) (Show Source): You can put this solution on YOUR website!
Hi,
:
Let n be the number of nickels, and d be the number of dimes.
From the first sentence:
(1) .05n + .10d = 11.2
Second sentence:
(2) n + d = 140
:
From equation 2, we subtract n from both sides:
(3) d = 140 - n
:
Substitute (3) into (1):
.05n + .1 (140 -n) =11.2
.05n + 14 - .1n = 11.2
-.05n = -2.8 (Multiply by -20 on both sides)
n = 56
:
Using equation #3:
d = 140 - 56
d = 84
:
--------------------
Cheers/
Saifoo.khan
einstein.saifoo@gmail.com

RELATED QUESTIONS
Kathy has $10.70 in a jar that only contains nickles and dimes. There are 120 coins in... (answered by richwmiller)

Billy has 16 coins in a jar. The jar contains only nickels and dimes. If the coins are... (answered by jorel1380)

A jar contains only nickels and dimes and there is 200 coins in the jar. The value is 14... (answered by ikleyn)

a jar of coins contains only nickels and dimes. There are 500 coins in the jar and the... (answered by JulietG)

a coin jar contains dimes and nickels only. In the jar, 3 out of 10 coins are dimes. if... (answered by jim_thompson5910,lynnlo)

A coin jar contains dimes and nickels only. In the jar 3 out of 10 coins are dimes. If... (answered by CubeyThePenguin)

Use substitution to solve Drew has a coin jar with a small collection of nickels and (answered by ikleyn)

A jar of change has 28 coins which is worth $2.60. If the jar only has nickels and dimes, (answered by macston)