Error Quiz
Practice quiz on Error (Numerical & Mental Ability). 10 exam-style questions with explanations.
About This Quiz
Error Quiz — Questions with Solutions
All 10 questions from this quiz with the correct answer and explanation. Attempt them yourself first, then open each solution to check your reasoning.
Q1.If the length of a square is measured with 2% error, the error in area is about
- A.2.04%
- B.4.04%
- C.4%
- D.2%
Show answer
Answer: B. 4.04%
(1.02)^2 - 1 = 4.04%.
Q2.Round 4.567 to two decimal places.
- A.4.60
- B.4.56
- C.4.57
- D.4.58
Show answer
Answer: C. 4.57
The third decimal is 7, round up.
Q3.The difference between 4.5 and 4.52 is
- A.0.002
- B.0.02
- C.0.2
- D.0.12
Show answer
Answer: B. 0.02
4.52 - 4.5 = 0.02.
Q4.Round 3482 to the nearest hundred.
- A.3000
- B.3480
- C.3400
- D.3500
Show answer
Answer: D. 3500
82 rounds up.
Q5.The absolute error in measuring 50 cm as 49.5 cm is
- A.1 cm
- B.5 cm
- C.0.05 cm
- D.0.5 cm
Show answer
Answer: D. 0.5 cm
50 - 49.5 = 0.5.
Q6.The percentage error if 50 is measured as 49 is
- A.2%
- B.0.5%
- C.5%
- D.1%
Show answer
Answer: A. 2%
1/50 x 100 = 2%.
Q7.Estimate 49 x 21 to the nearest hundred.
- A.900
- B.1100
- C.1000
- D.1200
Show answer
Answer: C. 1000
49 x 21 = 1029.
Q8.If a quantity is increased by 25% and then decreased by 20%, the net change is
- A.0%
- B.5% decrease
- C.5% increase
- D.1% decrease
Show answer
Answer: A. 0%
1.25 x 0.8 = 1.
Q9.1.999 rounded to one decimal place is
- A.2.1
- B.1.8
- C.1.9
- D.2.0
Show answer
Answer: D. 2.0
Rounds to 2.0.
Q10.Round 0.0456 to two significant figures.
- A.0.045
- B.0.05
- C.0.04
- D.0.046
Show answer
Answer: D. 0.046
Two significant figures give 0.046.
Frequently Asked Questions
Is Error Quiz free to attempt on AajExam?
Yes. Error Quiz is completely free. You only need a free AajExam account to track your score, view detailed solutions and unlock cross-attempt analytics.
How long does it take to complete Error Quiz?
Error Quiz runs on a 10-minute timer in real exam-style conditions. The clock starts the moment you click Start, mirroring the time pressure of the actual exam.
Are detailed solutions provided?
Yes. Every question on Error Quiz ships with a complete step-by-step solution, the underlying concept, and (where applicable) shortcut tricks. You can also discuss any question with the AajExam community.
Can I attempt Error Quiz multiple times?
Yes. You can attempt this quiz as many times as you like. Each attempt is recorded separately so you can track improvement in score, accuracy and time-management.
Which government exams does this quiz prepare me for?
Error questions appear regularly in SSC CGL, CHSL, MTS, GD; IBPS PO, Clerk; SBI PO, Clerk; RRB NTPC, Group D; UPSC prelims and most State PSC exams. The specific weightage varies by exam — check the exam pattern on the corresponding AajExam exam page for details.