Notebooks cost $1.20 each. this weekend they will be on sale for $0.80. what percentage is the sale?

Yosef can eat 21 jamuns while rose can eat just 15 . complete the blank. yosef can eat % more jamuns than rose.

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.