Short message monthly card

Analysis:

There are two kinds of markets in Beijing now:

1, M-Zone: 300 packages in 20 yuan; There are 500 packages in 30 yuan (excluding SMS).

Charge: 9: 00-23: 00 (call 0.25 yuan/minute) and 23: 00- 9: 00 the next day (call 0. 15 yuan/minute).

2.UP new forces: 15 yuan 200 packs, 300 packs of 20 yuan; There are 500 packages in 30 yuan (including SMS).

Charge: 0. 1 yuan/minute for all-day calls and 0.25 yuan/minute for local calls.

You can set up three long-distance special lines, and it only costs 0.25 yuan/minute to call these three special lines.