# 3i Infotech Placement: Sample Questions 192 - 193 of 1245

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## Question 192

### Question

MCQ▾

Two trains move in the same direction at 50 kmph and 32 kmph respectively. A man in the slower train observes the 15 seconds elapse before the faster train completely passes by him. What is the length of faster train?

Choice (4)

a.

50m

b.

100m

c.

120m

d.

75m

d.

### Explanation

Two trains are moving in the same direction with speed 50 kmph and 32 kmph.

So, net speed

A man in the slower train observes the 15 seconds elapse before the faster train completely passes by him.

We are asked to find the length of the faster train. Let it be x km.

So,

So, length of the train is 75 m.

## Question 193

Edit

### Describe in Detail

Essay▾

What is an Entity type?

### Explanation

• An entity is represented or defined by set of attributes.
• Attributes are the properties used to describe an entity.

Types of Entity:

• Strong Entity Types
• Recursive Entity Types
• Weak Entity Types
• Composite Entity Types or Associative Entity Types
• SuperType and SubType Entities

Different Entity Type in ER Diagram

 Entity Type in Image Entity Strong Entity Type Strong Entity Type Weak Entity Type Weak Entity Type Recursive Entity Type Recursive Entity Type Composite Entity Type Composite Entity Type (or)Associative Entity Subtypes and Supertypes Subtypes and Supertypes

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