Answer: C
Explanation:
\(\frac {x}{5} = 42 \Rightarrow 42 \times 5\) = 210
\(\frac {x}{4} = 35 \Rightarrow 35 \times 4\) = 140
210 – 140 = 70
Q2. The average age of 30 students in a class is 20 years. The average age of 25 students is 15. What is the average age of remaining students
Answer: D
Explanation:
Sum of age of 15 Students = \( (40 \times 20) – (25 \times 15) \) = 600 – 375 = 225
Average = \( \frac {225}{5}\) = 45
Q3. The average of nine number is x and the average of three of these is y if the average of the remaining three is z, then
Answer: A
Explanation:
\( x = \frac {3 y + 3 z}{9} \Rightarrow 3 x = y + z\)
Q4. If a, b, c, d, e, f, g are seven consecutive odd number,their average is
Answer: A
Explanation:
\( \frac {a + (a + 2) + (a + 4) + (a + 6) + (a + 8) + (a + 10) + (A + 12)}{7}\)
\( \frac {7 a + 42}{7}\) = a + 6
Q5. The mean of 1, 8, 27, 64, 125 ……… 1728
Answer: A
Explanation:
Sum of cube numbers = \( \frac {n (n + 1) (2 n + 1)}{6}\)
= \(\frac {12 \times 13 \times 25}{6}\)
= \(\frac {3900}{6}\) = 650
Answer: D
Explanation:
Total age of 6 members (4 years ago) = \(20 \times 6\) = 120
Now total age of the family = 120 + \((4 \times 6) \Rightarrow 120 + 24\) = 144
Total age of 7 members (now) = \(20 \times 7\) = 140
Age of the baby = 144 – 140 = 4
Q2. Average of ten positive numbers is x.If each number is increased by 12% then x is incresed by
Answer: B
Explanation:
\(\frac {\frac {120}{100} {x}_{1} + \frac {120}{100} {x}_{2} + … + \frac {120}{100} {x}_{10}}{10}\) = \(\frac {12}{10} x \)
Average is increased by 12 %
Q3. The average age of husband and wife was 30yr, 4 yr ago. What will be their average age at present ?
Answer: B
Explanation:
Avg of H and W age 4yr ago = 30
Present avg age of H and W = 30 + 4 = 34
Q4. The average weight of 20 students is 60kg.If the weight of the teacher is added, average is increased by 2kg.What was the teacher’s weight ?
Answer: C
Explanation:
\( \frac {x}{20} =60; x \)= 1200
\( \frac {x}{21} = 62; x \)= 1302
1302 – 1200 = 102
Q5. The average mark in 2 subjects is 35 and in three other subjects is 40. Then find the average mark in all the five matches ?
Answer: D
Explanation:
\( \frac {x}{2} = 35; x \)= 70
\( \frac {x}{3} = 40; x \)= 120
5 sub avg = \( \frac {(70 + 120)}{5} \)= 38
Answer: D
Explanation:
\( \frac {(15 \times 75) – (35 + 46) + (38 + 63)} {15} \) = \( \frac {(1125 – 81 + 101)} {15} \)
= \( \frac {1145}{15} \) = 76.33 = 76
Q2. Among the three number, the first is thrice the third number and the second number is half of the first number. If the average of the three number is 65.8 then find the third number
Answer: C
Explanation:
Let third num = \( x, {1}^{st} number = 3x, \) second no = \( \frac {3 x}{2} \)
\( \frac {[3 x + ( \frac {3 x}{2}) + x]} {3} \) = 65.8
\( \frac {11 x}{2} \) = 197.4
\( X = \frac {(2 × 197.4)} {11} \) = 35.89
Q3. The average weight of 3 students P, Q, and R are 84kg. Another student S joins the group and the average becomes 80kg. If another man T whose weight is 3kg more than that of S, replaces P, then the average weight of Q, R, S, and T becomes 79 kg then the weight of P is
Answer: A
Explanation:
P + Q + R = \( 84 \times 3 \) = 252
P + Q + R + S = \( 4 \times 80 \) = 320
S = 320 – 252 = 68
Q + R + S + T = \( 79 \times 4 \) = 316
Q + R + 2S + 3 = 316
S = 68, Q + R = 177
P = 252 – 177 = 75
Q4. The average of 5 consecutive number is 58.Find the first number ?
Answer: B
Explanation:
\( x + x + 1 + x + 2 + x + 3 + x + 4 = 58 \times 5 \) = 290
\( 5x + 10 \)= 290
\( X = 290 – \frac {10}{5} = \frac {280}{5} \) = 56
Q5. The average weight of 8 staff is increased by 3kg when one of them whose weight is 50kg is replaced by a new staff. The weight of the new staff is
Answer:
Explanation:
50 + \( (8 \times 3) \)= 50 + 24 = 74.
Competitive Exams – Study Guide  

Category  
Quantitative Aptitude 
Reasoning Ability 
General Awareness 
Computer Awareness 
English Knowledge 
Banking Awareness 
General Science 
World of Words 
Descriptive Test 
Competitive Exams – College Entrance Exams  

Category  Notification  
Diploma  NITC New Delhi  
PG  GATE 2020  
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Competitive Exams – Practice Sets  

Category  Quiz  
Quant Aptitude  Permutation and Combination  
Spotting Errors  
Profit and Loss  
Reasoning Ability  Puzzles  
Insurance Awareness  Insurance Awareness 
General Knowledge for Competitive Examinations  

Topic  Name of the Article 
GK – World  Agricultural Commodities Largest Producers 
International Borders  
GK – India  Indian High Courts 
Early Vedic Period – Ancient India Dynasties  
GK – Abbreviations  Insurance Domain Abbreviations 
Indian Government Policies Abbreviations 

GK – Banking & Insurance  Public Sector Banks – Headquarters and Taglines 
Pradhan Mantri MUDRA Yojana  
GK – Science & Technology  Indian Internet Service Providers 
Medical Science Discoveries 