Mathew scored 42 marks in Biology, 51 marks in Chemistry, 58 marks in Mathematics, 35 marks in Physics and 48 marks English. The maximum marks, a student can score in each subject, are 60. How much overall percentage did Mathew get in this exam?

B's marks = C's marks + 5% of 400
= 300 + 20 = 320

Now , A's marks = B's marks + 10% of 400
= 320 + 40 = 360

Let the positive number be N.

According to the question
N x (15+ 20)% = 126
? N x 35 = 126 x 100
? N = 12600/35 = 360
So, one-third of the number = 360/3 = 120

Let 1st number be M and 2nd number be M.
According to the question,
48% of M = 60% N
? (M x 48)/100 = (N x 60)/100
? M/N = (60/100) x (100/48) = 5/4
? M : N = 5 : 4

In such case, there is always decrease.
Given that, a = (common increase or decreased) = 7%

According to the formula,
Decreased Percentage = a²/100 %
= 7²/100 %
= 0.49%

Let the number of boys = B
and number of girls = G
Then, 10% of B = 1/4 of G
? B/10 = G/4
? B/G = 10/4 = 5/2
? B : G = 5 : 2

Net effect on area = -20 + 10 + [(-20 )(10)/100] %
= (-10 - 2) % = -12%
Now, after this mistake new area = (100 - 12)% of 200
= (88/100) x 200
= 176 sq cm

After removing 25% of blue balls,
Total blue balls left = 75% of 100
= (75/100) x 100 = 75

After removing 50% of red balls, total red balls left = 50% 0f 50 = (50 x 50) / 100 = 25
? Required percentage = [50/(75 + 25 + 50)] x 100
= (50/150) x 100
= 33¹/₃ %

Let cost prices of two article be 3N and 4N respectively then
(110% of 3N) / (4N + 4) = 3/4
? 1.1N / (N + 1) = 1
? 1.1N = N + 1
? 0.1 N = 1
? N = 10

Thus, cost price of the second article is 4 x 10 = ? 40

Let sale in 2008 = 100
Sale in 2009 = 20
Sale in 2010 = 100
? Required increases = [(100 - 20)/20] x100
= (80/20) x 100 = 400%

Let the total number of votes = N

According to the question,
75% of 98% of 75% of N = 9261
[? 2% votes were rejected]
? (N x 75 x 98 x 75) / (100 x 100 x 100) = 9261
? N = (9261 x 100 x 100 x 100) / (75 x 75 x 98) = 16800