Question 299196
Let the number of dimes be x
the number of quarters be y

x+y =20 

10x+25y=380 cents

10x+10y -(10x+25y)=200 -380

10x+10y-10x -25y=-180

-15y= -180

y=-180/-15

y=12 the number of quarters

20-12 = 8 will be the number of dimes