# 3i Infotech Placement: Sample Questions 818 - 820 of 1245

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## Question 818

### Question

MCQ▾Pipe A can fill in 20 minutes and Pipe B in 30 minutes and Pipe C can empty the same in 40 minutes. If all of them work together, find the time taken to fill the tank.

### Choices

Choice (4) | |
---|---|

a. | 8 minutes |

b. | minutes |

c. | 20 minutes |

d. | Question does not provide sufficient data or is vague |

### Answer

b.### Explanation

Pipe A can fill in 20 minutes and Pipe B can fill the same in 30 minutes.

Pipe C can empty the same in 40 minutes.

If all of them are working together, then in one day they can work,

So, working together they can complete the work in days.

## Question 819

### Write in Short

Short Answer▾What is the parameter substitution symbol used with INSERT INTO command?

### Explanation

- & parameter substitution symbol used with INSERT INTO.
- INSERT INTO command is not used before a substitution variable.
- It is used to add new records into a database table with values for all its column.
- Can be combined with a SELECT to insert records.

**Syntax of INSERT INTO command**

INSERT INTO table_name (column_name)

VALUE (values)

## Question 820

### Explanation

- Working set is the approximation of the set of pages that the process will access in the future and more specifically is indication of pages to be kept in main memory to allow smooth execution of process without page faults.
- The window of the working set of a process is the total number of pages the process has referred recently.
- The working set information W at time t is the collection of information referred by the process during the process time interval () .
- The units of information in question are considered memory pages.
- It determines if there is enough RAM in the system.
- If working set is smaller than RAM data the program frequently accesses is always in memory.