3/5:11/15. 27/40:18/35 помогите плиз

Question

3/5:11/15. 27/40:18/35 помогите плиз

Answer 1

3/5:11/15=3/5*15/11=3/1*3/11=9/11
27/40:18/35 =27/40*35/18=3/40*35/2=3/8*7/2=21/16=1 5/16=1,3125