is there any mistake?

[happys82]

1.In this section total of 16 personnel including a business manager, a chef, two assistant cooks, five waiters and four scullery workers give a service. Daily from two different service points refreshment and coctails are prepared for lunch and other special meetings for 750 persons.
[FONT=&quot]2. These computers can see all computers in the school. Teachers can easily reach announcements with the help of board on the wall. [/FONT]

 

[emsr2d2]

1.In this section total of 16 personnel including a business manager, a chef, two assistant cooks, five waiters and four scullery workers give a service. Daily from two different service points refreshment and coctails are prepared for lunch and other special meetings for 750 persons.

A total of 16 personnel (or staff), including a business manager, a chef, two assistant cooks, five waiters and four scullery workers, work in this section. Refreshments and cocktails are prepared daily for lunch and special meetings, for up to 750 people, from two different service points.

[FONT=&quot]2. These computers can see all computers in the school. Teachers can easily reach announcements with the help of board on the wall. [/FONT]

These computers are linked to all the computers in the school. Teachers can easily post announcements on the board on the wall.

See above. In sentence 1, the word order simply needed tidying up a little. In sentence 2, I wasn't sure how these two statements were connected - they don't seem to be relevant to each other. We don't really say "with the help of..." + an inanimate object. The board on the wall doesn't actively help the teachers make announcements, it's simply the medium through which the teachers do so.

 

[happys82]

Two statements aren't connected two each other.

Teachers can easily post announcements on the board on the wall.
I meant here that they can read any news from the board.

 

[emsr2d2]

Two statements aren't connected two each other.

Teachers can easily post announcements on the board on the wall.
I meant here that they can read any news from the board.

Ah, your original post said they can "reach" announcements, not "read" so I thought you meant that perhaps they could reach their students, but using the noticeboard.

In that case, "Any announcements for teachers will be posted on the [notice]board on the wall."