Answer:
There are 34 dimes and 6 quarters in the jar.
Step-by-step explanation:
1. Let's check the information given to us to answer the question correctly:
Number of dimes and quarters = 40
Total value of the 40 coins = US$ 4.90
2. How many of each coin are there?
x = Number of dimes
y = Number of quarters
System of equations:
x + y = 40
0.10x + 0.25y = 4.90
Solve for y on the 1st equation:
x + y = 40
y = 40 - x
Substitution of y for solving for x on the 2nd equation:
0.10x + 0.25y = 4.90
0.10x + 0.25 (40 - x) = 4.90
0.10x + 10 - 0.25x = 4.90
-0.15x = 4.90 - 10
-0.15x = -5.10
x = -5.10/-.015
x = 34 ⇒ y = 6
There are 34 dimes and 6 quarters in the jar.
