First Naukri Percentages Quiz -1

Ans: Let the initial price of Rakesh be Rs. 100 per unit and Rakesh's consumption be 10 units.
∴ Initial amount spent = 100 × 10 = Rs. 1,000
New price of lentils = 120% of 100 = Rs. 120 and new total amount spent = 108% of 1000 = Rs. 1,080
∴ New consumption = \frac{1080}{120} = 9 units
∴ Decrease in consumption = 1 unit
∴ % decrease = \frac{1}{10) \times 100 = 10%

Suppose the production of the company in the year 2016 be x.

Then production of the company in year 2020= x \times \frac{115}{100}\times \frac{115}{100}\times \frac{80}{100}\times \frac{125}{100} = 1.32x

∴ Increase % in the production in year 2020 = \frac{\left ( 1.32 - x \right )\times 100}{x} = 32%

Ans: Let the votes received by P and x & Q be y.

Now as per the given statements,

x – y = 400 .......(1)

\left ( \frac{87.5}{100} \right )\times x = y + \left ( \frac{12.5}{100} \right )\times x  ……… (2)

y = \left ( \frac{3}{4} \right )x ……. (3)

Using (3) to solve (1) we get

x - \left ( \frac{3}{4} \right )x = 400

x = 1600

And, y = 1200

Now, we know that P & Q collectively won 70% of total votes.

If the total number of registered voters in the village be M,

\left ( \frac{70}{100} \right )\times M = 1600+1200 = 2800

M = 4000

Ans: 5/6 corresponds to 83.33%.

Hence, the amount that she kept with him corresponds to 100 − (83.33 + 5 + 10) = 1.67% of the total amount with her. This corresponds to Rs. 850

Also, because she placed 10% in debentures and she got 10% interest, the amount obtained in interest = 10% of 10% of the amount with him i.e. 1% of the amount with her.

∴ Interest earned = \frac{\left ( 850 \times 1  \right )}{1.67} = 510

Ans: Original cost of a car and house = 500000 + 700000 = Rs. 12,00,000

New cost of car = 500000 × 0.85 × 0.87 × 0.89 = Rs. 329077.5

New cost of house = 700000 × 1.1 × 1.12 × 1.14 = Rs. 983136

∴ Total new cost = Rs. 13,12,213.5

∴ Change = increase of Rs. 1,12,213.5 ≈ Rs. 1,12,214

Ans: Let the salary of Vikash to Madhu be 4x and 9x respectively.

B.T.P,

9x \times \frac{145}{100} = 33930

x= 2600

Vikash's salary = 4x = 4 × 2600 = 10400

Ans: Let the maximum marks in each subject be 100.

∴ Yuvan Chowdhury's total score = 60% of (100 + 100 + 100) = 0.6(300) = 180

Also, 70% marks in a subject correspond to 0.7(100) = 70

Let Yuvan Chowdhury have scored 4x, 5x and 6x in math, English, and science

∴ 4x + 5x + 6x = 180

∴ 15x = 180 i.e. x = 12

Hence, his marks in the three subjects are 48, 60 and 72 .

Hence, he has scored more than 70 in exactly one subject

Ans: Let the original entry fee be ‘a’ and the number of people initially coming to the park be ‘b’.

Total income = a × b = ab

Now, reducing the entry fee by 35% in a park, the number of people coming to the park increased by 40%

∴ New entry fee = a - 35% of a = 0.65a

Number of people = b + 40% of b = 1.4 b

Total income = 0.65a × 1.4b = 0.91 ab

Decrease in income = ab – 0.91ab = 0.09ab

% decrease in income = \frac{0.09ab}{ab}\times 100%

⇒ % decrease in income = 9%

Ans: Let total number of students in the coaching be x

Then number of student in morning batches = 25% of x = 0.25x

number of student in midday batches = 35% of x = 0.35x

number of student in evening batches = 40% of x = 0.40x

number of passed students in morning batches = 2% of 0.25x = 0.005x

number of passed students in midday batches = 4% of 0.35x = 0.014x

number of passed students in evening batches = 5% of 0.40x = 0.02x

So total number of passed students = 0.005 + 0.014x + 0.02x = 0.039x

Therefore number of failed students = Total number of students – total number of passed students = x – 0.039x = 0.961x

Hence the percentage of failed students = \frac{0.961x}{x} = 96.1%

Ans: Let Zinc is formed at the rate of x% per microsecond and Sulphur is formed at the rate of y% per microsecond

Let when T = 0, then Zinc particle = 4 then the Sulphur particle = 5

When T = 1, \frac{x% of 4}{y% of 5} = \frac{5}{7}

28x = 25y

x : y = 25 : 28

Therefore, let Zinc is formed at the rate of 25x% per microsecond then Sulphur is formed at the rate of 28x% per microsecond.

The reqd. % = \frac{\left ( 28x - 25x \right )\times 100}{25x} = 12%