Database Administration Questions

The place which is designated as 0 degrees longitude is Greenwich, England.

Immutable classes are Java classes whose objects can not be modified once created. Any modification in Immutable object result in new object. For example is String is immutable in Java. Mostly Immutable are also final in Java, in order to prevent sub class from overriding methods in Java which can compromise Immutability. You can achieve same functionality by making member as non final but private and not modifying them except in constructor.

A UPS (Uninterruptible Power Supply) is a device that provides battery backup when the electrical power fails or drops to an unacceptable voltage level.

Small UPS systems provide power for a few minutes; enough to power down the computer in an orderly manner, while larger systems have enough battery for several hours.

For undo the action or last action [Ctrl + Z] is used.

The time complexity of sequential search is O(n)

Let the present ages of Kapil and Avanthi be K & A

Given difference in their ages = K - A = 9 years ...........(1)

After 7 years, K + 7 =  2(A + 7) ......(2)

K + 7 = 2A + 14

K - 2A = 7 ............(3)

K - A = 9 ....(1)

From (1) & (3),

-A = -2

=> A = 2 years

=> K = 9 + 2 = 11 years

Required, age of Kapil after 4 years = 11 + 4 = 15 years.

This is only possible when that doctor is boy's mother.