I think you have a typo in 1 a.
1b. OK
1c. 1c. 18/25=1/x= 1.38888888 = 1.39
1d. OK
1a. x/20=52,5/75= 14
1b. 13/16=x/100= 81.25
1c. 18/25=1/x= 1.38
1d. 25/18=1/x= .72
5 answers
1a. x/20=52.5/75=14
Right.
Thanks
You're welcome.