InfyTQ Ratio and Proportion Quiz 1

Solution:

Let y income be = 8x, y’s expenditure = 8x- 30

Let z income be 10x, z’s expenditure = 10x – 80

The ratio of expenditure = 4:5

Cross multiply 8:10 by 4:5 = 1

Now, cross multiply 4:5 with savings that is 30 and 80 = 320 and 150

X = 320 – 150 = 170

Y = 8* 170 = 1360 and Z = 10* 170 = 1700

Option B
Explanation
Volume of salt in mixture = 70% salt × volume of mixture litre and Volume of water in mixture = 40 - 28 = 12 liter
To decrease the salt percent by 40% Let, x water is added.
Then the volume of mixture liter
We know that, Volume of salt = 28 liters
Therefore,  Salt in a new mixture. But Now Salt percent in a new mixture decreases to 40%

Therefore, \frac{28}{40 + x}\times 100 = 40

2800 = 40(40 + x)

2800 = 1600 + 40x

x = 30

200
The ratio of shares of groups of men, women, and boys = 5:3:2
So share of 5 boys is = (2/10)*5000 = 1000
Share of one boy is = 1000/5 = 200

Let the side of a cube be 'a'

The total surface area of cube = 6a²

Total surface area of 3 cubes= 3 × 6a² = 18a²

After joining 3 cubes in a row,

length of Cuboid =3a

Breadth and height of cuboid = a

Total surface area of cuboid = 2 (3a² + a² + 3a²) = 14a²

The ratio of the total surface area of a cuboid to the total surface area of 3 cubes

= 14a² / 18a² =7/9

Hence, the ratio is 7: 9

let the salary of Raju is P
Then Ramu's salary is 3P
After 2 months Raju's salary becomes P(1+20/100)2 -- (1)
After 2 months Ramu's salary becomes 3P(1-10/100)2 --(2)
Ratio= (1)/(2) = 144:27 = 16:3

When 5000 is shared among p,and r in the ratio of 2:3:5 then,
p=(5000×2)÷10=1000
q=(5000×3)÷10=1500
r=(5000×5)÷10=2500
and if upon this 500 is added to each of them then
p=1500
q=2000
r=3000
then the new ratio will be
3:4:6

Let x litres of ₹10 milk and y litres if ₹11 milk
then
10x + 11y = 10.6(x+y)
0.4y = 0.6 x
x/y = 4/6 =2/3

Let the three parts be A, B, C. Then,

A : B = 2 : 3 and B : C = 5 : 8

= \left (5\times \frac{3}{5} \right ) : \left (8\times \frac{3}{5} \right ) = 3 : \frac{24}{5}

⇒A : B : C = 2 : 3 :\frac{24}{5} = 10 : 15 : 24

⇒ B = \left (98\times \frac{15}{49} \right ) = 30

We have,

Mixture of whiskey and water = 66 liters

Initial ratio of whiskey and water = 4:7

Changed ratio of whiskey and water = 2:3

Let the whiskey be 4x
and water be 7x

A/q

4x+7x = 66
=> 11x = 66
=> x = 66/11 = 6

Whisky = 4×6 = 24 litres
Water = 7×6 = 42 litres

Now,

4+x/7+x = 2/3

=> 3(4+x) = 2(7+x)

=> 12 + 3x = 14 + 2x

=> 3x - 2x = 14 - 12

=> x = 2

Then,

Whisky = 4+x = 4+2 = 6

Water = 7+x = 7+2 = 9

So,
Whiskey = 6 × 6 = 36 litres
Water = 9×6 = 54 litres

Hence,

Initial weight of whiskey = 24 litres
Changed Weight of whiskey = 36 litres

Added whiskey = 36 - 24 = 12L

Initial weight of water = 42 litres
Changed Weight of water = 54 litres

Added water = 54 - 42 = 12L

Using cross product rule, we get,

\frac{10}{3}:\frac{5}{4} = x:\frac{5}{2}

\frac{25}{6} = \frac{5x}{2}

\frac{25}{6}:\frac{2}{5} = x

\frac{5}{3} = x

x  =  5/3