Dell Percentage, Ration & proportion Questions

If boys = x and girls = y, then
Y * (10/100) = x/20
y/10 = x/20
x/y=20/10
=2/1

252.5 : 53 = (52)2.5 : 53
= 55 : 53 = 52 : 1 = 25 : 1

(1:2),(2:3),(3:4)
(1+2),(2+3),(3+4)
3,5,7
equal quantities of mixture
i.e. lcm of 3,5,7=105
105/3=35 , 105/5=21 , 105/7=15
(35*1,35*2),(21*2,21*3),(15*3,15*4)
(35,70),(42,63),(45,60)
so overall mixture ratio is
35+42+45:70+63+60
122:193

Hall capacity 200
10%vacant -- so 180 passengers waiting
40% i.e 72 are women
seating capacity of each flight = 2/3 *180
=120
after boarding flight a, 60% i.e 60/100 *200 =120 seats became vacant

so 80 people are still waiting
i.e. 100 people boarded the flight .

80/20 =4 air hostesses.

120-80 = 40 empty seats in flight b.

40:4 = 10:1

We know that for any diagonal in this rectangle
described that a^2 + b^2 = c^2.

Now, by walking the c^2 path,
he saved half the distance of b
we will say, and
call b the longer side, so we know:

c = a + b - b/2, or c = a + b/2

Now, putting this in to the first equation:

a^2 + b^2 = (a + b/2)^2

Expand:

a^2 + b^2 = a^2 + ab + b^2/4

Cancel:

(3/4)b^2 = ab

Divide by b:

(3/4)b = a

So, the ratio is 3:4.

If earlier he is getting Rs. 1 per hr and working
for 1 hr, income = Rs. 1
Now he is getting Rs 1.3333 per hr and
working for 0.66667 hrs

Then income for 0.66667 hrs = Rs. 0.8889.

If payment per hr is increased by 33.33 %
and working hours decreased by 33.33%,
then 11.11 % decrease in income.

The ratio of X and Y ages at present is 4:5.

Then, the ratio 20 years ago will not be
more than the ratio at present.

So, from the options 9:10 is not satisfying
=> its ratio is 0.9 which is greater than
present ratio of 0.8.

Let the third number be x.

Then, first number = 120% of x
=120x/100 = 6x/5


Second number =150% of x
= 150x/100 = 3x/2

Ratio of first two numbers = 6x/5 : 3x/2
= 12x : 15x = 4 : 5

Let the shares of A, B, C and D be Rs. 5x, Rs. 2x,
Rs. 4x and Rs. 3x respectively.

Then, 4x - 3x = 1000

x = 1000.

B's share = Rs. 2x = Rs. (2 x 1000)
= Rs. 2000.

Originally, let the number of seats for
Mathematics, Physics and Biology be 5x, 7x
and 8x respectively.

Number of increased seats are (140% of 5x),
(150% of 7x) and (175% of 8x).
7x, 21x/2 and 14x.
The required ratio = 7x :21/2x: 14x

14x : 21x : 28x

2 : 3 : 4.