Q: Jessica is six years older than Claire. In two years, Claire will be 20 years old. How old is Jessica now?
A: Claire's age now is 20 - 2 = 18 years old. Being 6 years older than Claire, Jessica is 18 + 6 = 24 years old. The answer is 24.

Q: Nadia walked 18 kilometers, which was twice as far as Hannah walked. How many kilometers did the two girls walk in total?
A: Hannah = (1 / 2) 18 = 9. 9 + 18 = 27 km. Together they walked 27 kilometers. The answer is 27.

Q: There are 50 more pens than notebooks on Wesley's school library shelf. If there are 30 notebooks on the shelf, how many notebooks and pens, does he have altogether?
A:
If there are 30 notebooks on the shelf, there are 50 + 30 = 80 pens on the shelf. Altogether, Wesley has 80 + 30 = 110 notebooks and pens on the shelf. The answer is 110.