Answer: there are 70 dimes and 40 quarters.
Step-by-step explanation:
A dime is 10 cents
A nickel is 5 cents
A quarter is 25 cents
Let x represent the number of dimes at the bottom.
Let y represent the number of quarters at the bottom.
The city park employee collected 1,850 cents in nickels, dimes, and quarters at the bottom of a wishing well. If there were 30 nickels, it means that
10x + 25y + 30 × 5 = 1850
10x + 25y = 1850 - 150
10x + 25y = 1700- - - - - - - - -1
There is a combined total of 110 dimes and quarters. It means that
x + y = 110
Substituting x = 110 - y into equation 1, it becomes
10(110 - y) + 25y = 1700
1100 - 10y + 25y = 1700
1100 + 15y = 1700
15y = 1700 - 1100
15y = 600
y = 600/15
y = 40
x = 110 - y = 110 - 40
x = 70