Please help me with 6-11

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.

Acompany had forty one employees and ordered nine hundred eighty uniforms for them. if they wanted to give each employees the same number of uniforms, how many more uniforms should they order so they don't have any extra

The half-life of a certain material is 0.002 second. approximately how much of a 14-gram sample will be left after 0.004 second? a. 12 grams b. 3.5 grams c. 0.06 gram d. 7 grams