Column equation

Suppose you take out 1 dime x and 50 dime y, then you take out 1 dollar coin15-x-y.

0. 1x+0.5y+ 15-x-y=7

Pack up, take it

9x+5y=80

y=(80-9x)/5= 16-2x+x/5

80-9x & gt； 0, x is an integer, and x is less than or equal to 8.

For y to be an integer, x/5 needs to be an integer. X can only take 0, 5.

x = 0y = 16 & gt； 15, give up.

x=5 y=7 15-5-7=3

65438+5 cents, 7 cents and 65438+3 0 yuan coins.