Question 1

Find the missing number in the series: 2, 6, 18, 54, ?

Accepted Answer

Step 1: Identify the pattern. Each term is multiplied by 3 to get the next term. Step 2: 2 × 3 = 6, 6 × 3 = 18, 18 × 3 = 54. Step 3: 54 × 3 = 162. Therefore, the missing number is 162.

Question 2

A number is divisible by both 4 and 9. Which of the following is definitely true about this number?

Accepted Answer

Step 1: A number divisible by both 4 and 9 must be divisible by their LCM. Step 2: Find LCM(4, 9). Since 4 = 2² and 9 = 3², they share no common factors. Therefore, LCM(4, 9) = 4 × 9 = 36. Step 3: So the number must be divisible by 36. Step 4: Check each option: (a) Divisible by 6? Not necessarily—36 is divisible by 6, but the question asks what is 'definitely' true. While 36 is divisible by 6, we need the strongest guarantee. (b) Divisible by 36? Yes, always—this follows directly from the LCM. (c) Divisible by 8? No—36 is not divisible by 8. (d) Divisible by 18? While 36 is divisible by 18, option (b) is the most direct and complete answer. Step 5: The number must be divisible by 36.

Question 3

Simplify: 36 ÷ 4 × 2 + 7 – 3

Accepted Answer

Step 1 (Division, left to right): 36 ÷ 4 = 9. Expression becomes 9 × 2 + 7 – 3. Step 2 (Multiplication): 9 × 2 = 18. Expression becomes 18 + 7 – 3. Step 3 (Left to right Addition/Subtraction): 18 + 7 = 25; 25 – 3 = 22. Therefore, answer is 22.

Question 4

Simplify: 18 ÷ 3 × (5 + 2) − 4² + 6

Accepted Answer

Step 1: Solve Brackets first: (5 + 2) = 7. Step 2: Solve Orders (Exponents): 4² = 16. Step 3: Division: 18 ÷ 3 = 6. Step 4: Multiplication: 6 × 7 = 42. Step 5: Now the expression is 42 − 16 + 6. Step 6: Left to right: 42 − 16 = 26, then 26 + 6 = 32. Therefore, answer is 32.

SSC CHSL Number System Questions

SSC CHSL Number System — Past Exam Questions

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