Take x, y and z coins as 1, 5, 1 yuan respectively.

z & lt7,

0. 1x+0.5y+z=7

x+y+z= 15

When z=4, it doesn't work either.

Z=3，x=5，y=7。

Z=2, z= 1 is invalid.

So take five 1 jiao, seven 50 jiao and three Zhang Yiyuan.