First Naukri Ratio and Proportion Quiz -1

Ans: We have been given that alloy X contains platinum and brass in the ratio 2 : 1. Let there be 21x units of X.

So it will have 14x units of platinum and 7x units of brass. Let there be 21y units of alloy Y. So we have 9 units of brass and 12 units of zinc. Let these two be mixed to get the desired alloy.

Hence, the total amount of platinum in alloy Z will be 14x and total amount of zinc will be 12y. We have been given that

\frac{14x}{12y} = \frac{5}{6}

\frac{x}{y} = \frac{5}{7}

Thus alloys X and Y must have been mixed in the ratio 5 : 7

Thus, the share of brass in the final mixture = \frac{(35+63)}{252}

                                = \frac{49}{126}

Ans: Let the income of Manisha in 2020 and 2019 be 3x and 5x respectively.

Let the income of Phoebe in 2020 and 2019 be 3y and 2y respectively

Since, the ratio of their income in the year 2019 was 5 : 4

5x : 2y = 5 : 4

2x = y

The sum of their incomes in 2020 is Rs. 10242

3x + 3y = 10, 242

9x = 10, 242

x = 1,138 and y = 2276

Phoebe’s income for the year 2019 = 2y = Rs. 4552

Ans: As they together have 12 plums, each person gets a share of 4 plums. Abhi took 4 plums as his share and paid 12 coins of the 4 plums. 

1 plum is given by Bikash and 3 plums are given by Ranbeer.

The ratio of plums of Ranbeer and Bikash = 3 : 1.

They must be paid in that ratio i.e., 3 : 1

Hence, the number of coins that Ranbeer should get = \frac{(3 \times 12)}{4} = 9 coins

Ans: Let the score of the topper be T.

Total score of the 52 students = 52 × 85 = 4420

Total score of the remaining 47 students after scores of the best five performers are removed = 47 × 83 = 3901

Total score of the top five students = 4420 – 3901 = 519

T + (total score of the next 4 top scores) = 519

T is the maximum when the total score of the next 4 top scorers is minimum.

Total score of the next 4 top scorers has a minimum value of 80 + 81 + 82+ 83 = 326 (since all the top 5 scores are distinct) and the least is 80.

T has a maximum value of 519 – 326 = 193

Ans: Ratio of the number of coins of denominations Rs. 1 : Rs. 2 : Rs. 5 = 5 : 7 : 6

Let, the number of coins of Rs. 1, Rs. 2 and Rs. 5 in the bag be 5x, 7x and 6x.

Since, the total value of Rs. 1 coin in the bag is Rs. 15

So, the number of coins of Rs. 1 in a bag = 15

5x = 15 , ⇒ x = 3

Therefore, number of Rs. 5 coins in the bag = 6x = 18

So, required value of Rs. 5 coins = 6 × 3 × 5 = Rs.90

Ans: Let the children be P, Q, R and S and mother be F

Cakes with P : Q : R= 3 : 7 : 11

Let the number of cakes be 3k, 7k and 11k

Total cakes with three eldest children = 21k

Cakes with F and S = 3 × 21k = 63k

Total cakes = (21k + 63k) = 84k

Cakes with F : (P + Q + R + S) = 3 : 4

Total 7 units of cake = 84 k

1 unit = 12k

Cake with F = 3 × 12k = 36k

Cake with S = (63k – 36k) = 27k

27 k = 81 → k = 3

Total number of cakes = 84k = 84 × 3 = 252

Ans: Let the XUV be rented for 8 hours or less.

Then the number of hours it is rented for \frac{800}{100} = 8 hours

But if it charged Rs. 8 per km, the amount that should paid be 120(8) = 960

But he paid only Rs. 800

The car is rented for more than 8 hours

Number of hours = \frac{800}{80} = 10 hours

If it is charged at Rs. 6 per km, the amount that should be paid would be 120(6) = Rs. 720 which is less than s. 800

Akshay rented the XUV for 10 hours.

Ans: Let the strength of IT1 = 16k and that of IT2 = 8k

Section IT1 ratio of Boys: girls = 3 : 1 → boys = 12k and girls = 4k

Section IT2 ratio of boys: girls = 3 : 5 → boys = 3k and girls = 5k

IT1 + IT2 – boys = 15k and girls = 9k

Maximum number of students in a row = HCF (15k, 9k) = 3k → 3k = 96 → k=32

Difference between boys of section IT1 and IT2 = 12k – 3k = 9k → 9 × 32 = 288

Ans: Let, marks obtained by Mukulika in theory and total marks of theory be ‘7x’ and ‘10x’ respectively

So, total marks (theory + practice tests) = 10x + 2x = 12x

Marks obtained by Mukulika (theory + practice tests) = 7x + 2x = 9x

So, reqd. ratio = \frac{9x}{12x} = \frac{3}{4} = 3:4

Ans: Let the total number of buyers be 100

Potstickers buyers = 100*1/4 = 25

Kale buyers = 100*3/4 = 75

The increase in no. of buyers after the trend,

Potstickers buyers = 25*8/100 = 2

And, Kale buyers = 60*10/100 = 6

Hence, total buyer ratio will be 27:81 = 1:3