COURSE MODULE NAME PERCENTAGES

% decrease = (1.25-1)/1.25 X 100 = 20%
8. % change in area = 1.2 X 1.2 (since area = side X side)
= 1.44 => 44%.
9.It is equivalent to 1.25 decreased to 1. So 20% decrease.
10. Valid Votes:
A got 56% => B got 44%
Difference = 12% = 48000
So, 100% = 400000. These are valid votes.
But valid votes are only 80% of total votes.
So, 80% of total votes = 400000 => total votes = 500000
11.Total money = Rs. 300.
Saving of the lady = 10% of 300 = 30/-
With 30/- she bought 5 kg sugar => each kg costs Rs. 6/-
12.In 20lt, salt = 20% => 4 lt.
New volume = 18 lt (2 lt evaporated)
So, new % = 4/18 X 100 = 22.22%
13.% correction = (58-46.4)/58 X 100 = 20%
14.Three successive decreases of 20%, 20% and 10% => 0.8 X 0.8 X 0.9 = 0.576
Again 10% decrease => 0.576 – 0.1 = 0.476.
So, 0.476 x = 9520 => x = 20000.
15.Total discount = 0.9 X 0.8 X 0.7 = 0.504 of actual price.
So, price = 0.504 X 10000 = 5040.
16.In 10 lt, alcohol is 10% = 1 lt.
Let x lt alcohol is added.
So, (1+x)/(10+x) = 20% = 1/5 => x = 1.25 lt.
17.A = 2B and B = 3C (since 200% more)
ð A = 6C => 500 % more.
18.50% of max marks – 40% of max marks = 25
ð max marks = 250
Pass marks = 40% of max + 10 => 100 + 10 = 110.
19.A = 1.2 B => B = A/1.2 => 0.8333A => 16.66%.
(OR) Decrease from 1.2 to 1 => 16.66%.
20.1.1 X 1.1 X x = 12100 => x = 10000.
21.Salt = 15% of x = 0.15x (x = volume of solution)
Now, 0.15x/(x-30) = 20% = 1/5 (since 30 lt evaporated)
ð x = 120 lt
22.20% empty => 80 % full = 240 lt => 20% = 60 lt
23.A => 1.4 X 1.4 = 1.96
B => 1.9 => 6% difference.
24. From 1960 to 1975, in 15 years population doubled every 5 yrs => three times
So, 2 X 2 X 2 = 8 times => 700% more.
25.[(75% X 60) + (x% X 20)] / 80 = 80% => x = 95. (since required is 80%)
(OR) 60 out of 80 is 3/4. So, (3/4 X 75) + (1/4 X x) = 80 => x =95.
Percentages
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