翻译:有3个学生用电脑搜寻信息资料

当然不对 . 分析你那句子的主谓宾,2个are又不是从句.
There are 30 student searching for information with computer

There are 3 students searching for information on computers.

30 students are collecting (searching for) information using the computers.

不对，两个谓语动词了
应该是：there are 30 students using computers to search for information

不对，给你个参考：There are three students in search of information by computer.