Help me please im grade 8 and that qustion id from revel

Liesl grew 7/12 of a foot in one year. her little sister grew 1/3 of a foot during that same year. how much more did liesl grow than her little sister did

If 1/2+2/5s=s-3/4,what is the value of s? a. s=3/4 b. s=25/12 c. s=-25/12 d. s=-3/4

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?