Help!!!!A few questions about percentage(10 points)

1.
1+25% --> 1.25
1.25* (1-25%) = 1.25*0.75 = 0.9375
Loss 0.0625
Gain percent = -6.25%

2.
1+35% --> 1.35
1.35* (1-20%) = 1.35*0.8 = 1.08
Gain 0.08
Gain = 8%

3.
Mary(M) = John(J) * (1+20%)
M = 1.2J
J = M/1.2 = M*(1-x%)
J = 0.8333M
ie. (1-x%) = 0.83333
x% = 16.6667%
x = 16.6667 (to 4 d.p.)

4.
B+30% = A
C+30% = B
(C+30%)+30% = A
1.3C*1.3 =A
C*1.69 =A
A is 69% greater than C

5.
Area = Side(s)*Side
(1.2x)^2 = 1.44
Area increase 44%.

1. If the original price of an article is $ y and is raised by 25%,
the new price would be:
$Y x (100% + 25%) = $Y x 1.25 = $1.25Y

Later, this item is sold at 25% discount of the new price,
the final sale price is $ 1.25Y x (100 % - 25%) = $ 1.25Y x 0.75 = $ 0.9375Y

The final price is 0.9375 = 93.75% of the original price of an article.
The gained percentage would be:

(93.75% - 100%) = - 6.25%

The final sale price actually resulted a loss of 6.25% of the original price.


2. The cost price of a dress is $ D.
The selling price of the dress is 35% more than its cost price:
$ D x (100% + 35%) = $ D x 1.35 = $ 1.35D

Now it is sold at a discount of 20% of the selling price, giving the final price.
The final price would be:
$ 1.35D x (100% - 20%) = $ 1.35D x 0.80 = $ 1.08D

The final price is 1.08 = 108% of the original price of the dress.
The gained percentage would be:

(108% - 100%) = 8 %

The final sale price resulted a gain of 8% of the original price of the dress.

3. Mary's age is M, and she is 20% older than John (John's age is J).
Therefore:
M = (100% + 20%)J
M = 1.2J

Now we have to find out how much younger in % John is compared to Mary:
If:
M = 1.2 J
then:
J = M/1.2
J = 0.83 M

John's age is 83% of Mary's age, and therefore John is
100% - 83% = 17% younger than Mary.

4. A is 30% greater than B, and B is 30% greater than C.

B is 30% greater than C, therefore:

B = 1.3 C

If A is 30% greater than B, then:

A = 1.3 B

Since B = 1.3 C

Then A = 1.3 x 1.3C
A = 1.69 C

So, A is (169% -100%) = 69% greater than C

5. Side of the original Square is 1S
If the side of a square is increased by 120% (1.2 times of original length), the length for side of the new square = 1.2 S cm

Area of square = length of side x length of side

Area of original square = 1S x 1S = 1S

The Area for the new square = 1.2S x 1.2S = 1.44S

Therefore, there is a 144% increase in area.