1) Frank is 8 years older than her sister. In three years, he will be twice as old as she is. How old are both of them now?

2) A pharmacist has 8 liters of a 15% solution of acid. How much distilled water must she add to reduce the concentration of the acid to 10%?

3) What % is 24 of 192?

4) Nancy ran a distance of 3.8km in 55min. What is her speed?

5) How much is a car when 8 cars cost $341, 360 ?