Kayla is given a monthly allowance she puts 40% of the money directly into her savings account she spends $15 at the movies with her friends at the end of the month if she has $3 left how much is her monthly allowance

The perimeter of △cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.