Please help i have been on this for hours.

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

If rt is greater than ba, which statement must be true ?