A33.33 percent decrease followed by a 50% increase. greater or larger that original amount?

Ithink i know it but i want to be sure so can you me out ?

Solve for n. round to the tenths place, if necessary. 14.2 cups of flour6 loaves of bread= 20 cups of flour n

Whoever gets this right gets the ! the half life of a soul smelling substance is 4 years. if you have 8 oz of this strange substance, how much of it will you have after 20 years? show work.