Acoin bank has 250 coins dimes and quarters worth 39.25 how many of each type of coins are there?

Set up a system of equations.

0.10d + 0.25q = 39.25
d + q = 250

Where 'd' represents the number of dimes, and 'q' represents the number of quarters.

d + q = 250

Subtract 'q' to both sides:

d = -q + 250

Plug in '-q + 250' for 'd' in the 1st equation:

0.10(-q + 250) + 0.25q = 39.25

Distribute 0.10:

-0.10q + 25 + 0.25q = 39.25

Combine like terms:

0.15q + 25 = 39.25

Subtract 25 to both sides:

0.15q = 14.25

Divide 0.15 to both sides:

q = 95

Now plug this into any of the two equations to find 'd':

d + q = 250

d + 95 = 250

Subtract 95 to both sides:

d = 155

So there are 95 quarters and 155 dimes.