The cost of setting up a magazine is Rs. 2800. The cost of paper and ink etc is Rs. 80 per 100 copies and printing cost is Rs.160 per 100 copies. In the last month 2000 copies were printed but only 1500 copies could be sold at Rs. 5 each. Total 25% profit on the sale price was realized. There is one more resource of income from the magazine which is advertising. What some of money was obtained from the advertising in magazine?

Area of equilateral triangle = ?3/4 a² = 4?3.
? a² = 16
? a = 4 cm

Here, n = 2, m =10, T₁ = 6 yr, T₂ = ?
? T₂ = [(m - 1) / (n - 1)] x T₁
= [(10 - 1)/(2 - 1)] x 6
= 54 yr

Given, SI₁ - SI₂ = 110,
T₁ = 2 Yr,
T₂ = 1 yr, R₁ = 8%, R₂ = 5%

According to the question,
[(P x 8 x 2)/100] - [(P x 5 x 1)/100] = 110
? 11P/100 = 110
? P = ? 1000

Let the positive number be N.
According to the question,
N + 10 = 200 / N
? N² + 10N = 200
? N² +10N - 200 =0
? (N - 10)(N + 20) = 0
? N = 10 & N= -20
But N not equal to -20 since N is a positive number
So, the required number is 10

Let the sum be p
Then, for R = 5%
SI = (4p - p) = 3p
? 3p = (P x 5 x T)/100 = PT/20
? T = 60 yr

Again, for another rate (R)
SI = (8P - P) = 7P
? 7P = (P x R x 60)/100
? R = (7 x 100)/60 = 35/3%
= 11²/₃ %

Here, P = ? 65800, R = 14% T = 4 yr
Hence, SI = (65800 x 14 x 4) / 100 =? 36848

? Required amount = P + SI
= 65800 + 36848
= ? 102648

Cost of 5 pens + 8 pencils = ?31
On multiplying by 3
15 pens + 24 pencils = 3 x 31 =
?15 pens + 24 pencils = 93

Given that, a = 8 cm, b = 10 cm and c = 12 cm

We know, that
s = (a + b + c)/2
= (8 + 10 + 12)/2
= 30/2 = 15 cm

? (s - a) = (15 - 8) = 7 cm
(s - b) = (15 - 10) = 5 cm
(s - c) = (15 - 12) = 3 cm

? Area = ?s(s - a) (s - b) (s - c)
= ?15 x 7 x 5 x 3
= ?1575
= ?25 x 63
= 5?63 cm

Let each sum be ? P then,
(P x 10 x 5)/100 - (P x 10 x 4)/100 = 220
? P/10 = 220
? P = 2200
Hence, each sum is ? 2200.

Let the number be N.
According to the question,
N - (N x 3/4) =163
? N/4 =163
? N=652