Maths Quiz for KVS and NVS Exams 2016

Q1. Anil had to do a multiplication. Instead of taking 35 as one of the multiplies, he took 53. As a result the product went up by 540. What is the new product?
(a) 1050
(b) 540
(c) 1440
(d) 1590
Sol.
Let the number be x.
Increase in product = 53x – 35x = 18x = 18x = 540 ⇒ x = 30
Hence, new product = 53 × 30 = 1590. Hence, option (d) is the answer.

Q2. What is the least number of soldiers in a regiment, such that they stand in rows of 18, 15 and 25 and also from a solid square?
(a) 1800
(b) 225
(c) 900
(d) None of these
Sol.
Number of soldiers should be a multiple of 18, 15 and 25 ⇒ Number should be a multiple of LCM (18, 15, 25)
Now lowest multiple of 450 that is a perfect square = 900. 

Q3. The average weight of 5 apples is 100 g and the average weight of 4 oranges is 80 g. If 2 apples and 2 oranges are picked from them that average weight is found to be 85 g. What is the average weight of the remaining apples and oranges?
(a) 88 g
(b) 90 g
(c) 96 g
(d) 95 g
Sol.
Weight of 5 apples = 500 g
Weight of 4 apples = 320 g
Weight of 2 apples and 2 oranges picked = 340 g
So, weight of 3 apples and 2 oranges remaining = (500 + 320 – 340)g = 480 g
Average weight = 480/5 = 96 g

Q4. In an exam the average was found to be p marks. After deducting typographical error the average marks of 94 students reduced from 84 to 64. Due to his the average came down by 18.8 marks? What was the number of students who took the exam?
(a) 100
(b) 90
(c) 110
(d) 120
Sol.
Number of students = (84 – 64) × 94/18.8 = 100

Q5. A shopkeeper sells his articles at CP but uses a faulty balance which reads 1000 gm for 750 gms. What is his actual profit percentage?
(a) 33.33%
(b) 25%
(c) 16.66%
(d)  14.28%
Sol.
Since while selling, 750 g = 1 kg
So, 250 gms = 1/3 kg
So, profit = 1/3 = 33.33%

Q6. A seller buys 50 kg oranges for Rs 525 and gains a profit equal to the selling price of 10 kg of oranges. Find the selling price per kg of oranges (Rs/kg).  
(a) 12.60
(b) 11.60
(c) 10.20
(d) 13.125
Sol.
Assume that the selling price per kg = Rs. X/kg
50X – 525 = 10X ⇒ 40X = 525
So, X = Rs. 13.125 kg

Q7. The students in three sections of IIML are in the ratio 2 : 3 : 5. If 20 students are increased in each section, the ratio changes to 4 : 5 : 7. The total number of students in the three sections before the increase are-
(a) 75
(b) 90
(c) 100
(d) 150
Sol.
Go through the options. Since the sum of ratios = 10, so total number of students should be multiple of 10. Now check the options one by one.            

Q8. A bag contains Rs 216 in the form of one rupee, 50 paise and 25 paise coins in the ratio of 2 : 3 : 4. The number of 50 paise coins is:
(a) 96
(b) 144
(c) 114
(d) 141
Sol.
Let number of one-rupee coins = 2 K
Number of 50-paise coins = 3 K
Number of 25-paise coins = 4 K
2K × Rs. 1 + 3 K × Rs. 0.5 + 4K × Rs. 0.25 = Rs. 216
⇒ 2 K + 1.5K + K = 216
K=48
The number of 50 paise coins=3K=144

Q9. Three years ago the average age of a family of 5 members was 17 years. With the birth of a new baby, the average remains the same even today. Find out the age of the baby.
(a) 1 year
(b) 3 years
(c) 2.5 years
(d) 2 years
Sol.
Present age of 5 members
= (5 × 17 + 3 × 5) years.
= 100 years
Present age of 5 members and a baby
= 17 × 6 = 102 years.
∴ Age of the baby = (102 – 100) years.
= 2 years.

Q10. A batsman in his 17th innings, makes a score of 85 runs, and thereby, increase his average by 3 runs. What is his average after the 17th innings? He had never been ‘not out’.
(a) 47
(b) 37
(c) 39
(d) 43
Sol.
Average score before 17th innings
= 85 – 3 × 17 = 34
∴ Average score after 17th innings
= 34 + 3 = 37.