Placement Papers - MCQ Practice Questions

A constructor is used to initialize objects of a class with default or specified values

The 'final' keyword prevents a class from being subclassed or inherited

ArrayList provides O(1) random access, while LinkedList provides O(n) access

HTTP stands for HyperText Transfer Protocol, the foundation of data communication on the web

MongoDB is a NoSQL database. MySQL, PostgreSQL, and Oracle are relational SQL databases

z-index controls the stacking order of overlapping elements on a webpage

The typeof operator returns 'number' for numeric values in JavaScript

30 meters / 5 = 6 meters per piece

Let number = x. 30% of x = 45. 0.30x = 45. x = $\frac{45}{0}$.30 = 150

Total balls = 5. Red balls = 3. Probability = $\frac{3}{5}$

Area of square = side² = 5² = 25 cm²

15% of 200 = ($\frac{15}{100}$) × 200 = 0.15 × 200 = 30

Let numbers be 3x and 4x. 3x + 4x = 70. 7x = 70. x = 10. Numbers are 30 and 40

Factors of 24: 1,2,3,4,6,8,12,24. Factors of 36: 1,2,3,4,6,9,12,18,36. GCD = 12

Each number is multiplied by 2. 5×2=10, 10×2=20, 20×2=40, 40×2=80

Original speed = $\frac{300}{5}$ = 60 km/h. New speed = 60 × 1.2 = 72 km/h. Time = $\frac{360}{72}$ = 5 hours

Rate of A = $\frac{1}{12}$, Rate of B = $\frac{1}{15}$. Combined rate = $\frac{1}{12}$ + $\frac{1}{15}$ = $\frac{5}{60}$ + $\frac{4}{60}$ = $\frac{9}{60}$ = $\frac{3}{20}$. Time = $\frac{20}{3}$ = 6.67 hours

Selling Price = Cost Price × (1 - Loss%). SP = 500000 × (1 - 0.15) = 500000 × 0.85 = Rs. 4,25,000

Amount = P(1 + R/100)^n = 10000(1 + $\frac{10}{100}$)^2 = 10000(1.1)^2 = 10000 × 1.21 = Rs. 12,100

Sum of first n natural numbers = n(n+1)/2. Sum = 20×$\frac{21}{2}$ = 210. Average = $\frac{210}{20}$ = 10.5