Adding Decimals Review

What is the least common denominator of 

$$\frac{1}{4}$$  and  $$\frac{2}{5}$$  

What is the least common denominator of  $$\frac{6}{8}$$  and  $$\frac{4}{12}$$   

$$\frac{2}{6}+\frac{1}{2}$$  

$$\frac{9}{10}-\frac{3}{4}$$  

Blake had 2/3 of a cake left after his birthday party. His sister, Bethany, ate 1/6 of the leftover cake. How much cake is left?

Jessica rode her bike $$8\ \frac{5}{9}$$   miles last week and $$5\ \frac{1}{3}$$  miles this week. How many miles did Jessica ride last week and this week combined?

Pam had $135.62 in her bank account. She deposited $58.90. How much money does she have in her account now?