Pencil box 12.6 yuan each, eraser 2.45 yuan each, pen 7.50 yuan each, ballpoint pen 2.90 yuan each, schoolbag 35.60 yuan each, ruler 2.85 yuan each.

(1) How much does it cost to buy a pen and ruler?

I have five yuan. Is it enough to buy an eraser and a ballpoint pen?

I bought a pencil-box and a schoolbag, paid 50 yuan, and got the change of 2.20 yuan, right?