Ну помогиите N3 пожалуйста

$\frac{99* \frac{1}{66}}{18: \frac{9}{10} } : \frac{6 \frac{3}{4} :3 \frac{3}{8} }{40: \frac{8}{9}*5 \frac{5}{9}*1 \frac{3}{5}} =15$

1) $99* \frac{1}{66} = \frac{3}{2}$
2) $18: \frac{9}{10} = \frac{18*10}{9} =2*10=20$
3) $\frac{3}{2} :20= \frac{3}{2*20} = \frac{3}{40}$
4) $6 \frac{3}{4} :3 \frac{3}{8} = \frac{27*8}{4*27} =2$
5) $40: \frac{8}{9} = \frac{40*9}{8} =5*9=45$
6) $45*5 \frac{5}{9} = \frac{45*50}{9} =5*50=250$
7) $250*1 \frac{3}{5} = \frac{250*8}{5} =50*8=400$
8) 2:400= $\frac{1}{200}$ =0,005
9) $\frac{3}{40} : \frac{1}{200} = \frac{3*200}{40} =3*5=15$