Solution:

Total percentage in eight examinations = 55
Total marks obtained = 55% of Maximum marks (8x100) = 55*800/100 = 440
Now, she scored 15% of these marks in Mathematics

Thus the score in mathematics = 440*(15/100) = 66

Hence, Anabelle scored 66 marks in Mathematics.

Solution:

Original are of the rectangle = l*b where l= length and b = breadth
After the sides are increased by 100%, the area will increase by
= (((2l*2b)-(a*b))*100) / (a*b) = 300%

Solution:

Let us assume that the initial price was Rs.100
Then after reducing it 30% the price will be Rs.70

To make it back to Rs.100, the price must be increased by
100*30/70 = 300/7 % = 42.86%

Solution:

Total games won by the team = 30 percent of 60 = 18
Now, the team wins continuous matches and raises winning % to 50
Thus, ((18 + x) / (60 + x)) * 100 = 50
(18 + x) / (60 + x) = 1/2
x = 24
Thus the team must have won 24 matches to raise the winning percentage to 50 percent.

Solution:

4 Kg

Explanation:
2% of 100kg = (100 - 50)% of x
2kg = x/2

=> x = 4kg (answer)

Solution:

Let one part denotes 10 lts.
Thus C contains 60 lts of liquid A and 40 lts of liquid B

Now amount of petrol will be = (25*60/100) + (30*40/100) = 27 lts.

Thus the percentage of petrol = 27%

Solution:

If the seller is buying at Rs.12/liter and mixing it with 20% of water and selling it for Rs.15/liter, he is selling the thus formed 1.2 liters of mixture at Rs.18

Thus the percentage of his gain is 50%.

Solution:

Let us assume that the purchase price is Rs. 100, then the selling price at the loss of 12 1/2 % will be Rs. 87.5.

Thus the ratio of purchasing price and selling price when the loss is 12 1/2 %
= 100/87.5 = 8/7 or 8:7.

Solution:

There is a simple way that can simplify the problem

Let us just assume that the number of employees are 100
Then the total number of men will be 35% of 100 = 35
Total number of women will be 100 - 35 =65

Now 20% of 35 = 7
And 40% of 65 = 26

Thus the number of employees that went to the trip = 33%

Solution:

Let us assume that there are 100 customers
Then there will be 40 percent people who will want to purchase items i.e. 40 people.
Now, fifteen percent of them wants to purchase mobile phones which means that 0.15*40 = 6 people want to purchase mobile phones which is 6 percent of the total customers.

Thus 6 % of people want to purchase mobile phones.