From Email

Mathematics Challenge

If you are an Engineer, you should be able to solve it within 3 minutes or less (30 seconds); If you are an Architects, perhaps you will need 3 hours; If you are a Doctor, perhaps you will need 6 hours; If you are an Accountant, maybe 3 months; If you are a Lawyer, maybe you can never find the answer.

|---+----+----+------+------|
| 2 | 3 | 4 | 15 | 12 |
|---+----+----+------+------|
| 3 | 4 | 5 | 28 | 20 |
|---+----+----+------+------|
| 4 | 5 | 6 | 45 | 30 |
|---+----+----+------+------|
| 5 | 6 | 7 | 66 | 42 |
|---+----+----+------+------|
| 6 | 7 | 8 | ? | 56 |
|---+----+----+------+------|

Find out the number in "?", it is the number to open the attached document.

Once you found the answer, please add your name into the attached document and forward to your friend.

Have fun!! (^__^)


====================================================================================

一項數學挑戰

這是項數學挑戰！有這麼一種說法：
你若是工程師，你應該可在三分鐘內（３０秒左右吧）解開這道題；你若是建築師，
給你三小時；你若是醫生，給你六小時；你若是會計師，三個月吧∼假若你是律 師，
大概永遠也解不出來。

請找出 "？" 格中的數字, 它即是開啟附件檔案的密碼．．．

|---+----+----+------+------|
| 2 | 3 | 4 | 15 | 12 |
|---+----+----+------+------|
| 3 | 4 | 5 | 28 | 20 |
|---+----+----+------+------|
| 4 | 5 | 6 | 45 | 30 |
|---+----+----+------+------|
| 5 | 6 | 7 | 66 | 42 |
|---+----+----+------+------|
| 6 | 7 | 8 | ? | 56 |
|---+----+----+------+------|
答案就是密碼，可以打開附件檔案。

你若能順利解題，請將你的名字加上，存檔後再寄給你的朋友^^


**Answer is 91