Marked price of the monitor = Rs 15600
Sales price of the monitor = Rs 12480
\(\therefore\)Discount = [Marked price] - [Sales price]
= Rs 15600 - Rs 12480 = Rs3120
\(\therefore\)Discount per cent = \(3120\over 15600\)x 100% = 20%

Rs 10810.94

Given ratio = 2 :3
∴ Percentage =\((\frac{2}{3}\times100)=(\frac{200}{3})=66\frac{2}{3}\)%

Rs 386400

Rs 1200

Let Chameli had total money be Rs x.
Percentage of money spent by Chameli = 75%
Chameli had left money after spending = (100 - 75)%
= 25%
But money left = Rs 600             [given]
∴ 25% of x = 600
⇒ \(\frac{25}{100}\times x=600 \Rightarrow x=\frac{600\times100}{25}=2400\)
Hence, Chameli had Rs 2400 in the beginning.
 Alternate Method
Let total money with Chameli at the beginning be Rs 100.
Expenditure money = 75% of total money
\(= Rs(\frac{75}{100}\times100)=Rs 75\)
Money left = Rs 100 - Rs 75=Rs 25
Now, if saving is Rs 25, then money at the beginning = Rs 100 
If saving is Rs 1, then money at the beginning = Rs \(\frac{100}{25}\)
If saving is Rs 600, then money at the beginning
\(= Rs (\frac{100}{25}\times 600)=Rs(4\times 600)= Rs 2400\)
Hence, total money at the beginning with Chameli was Rs 2400.

Let the cost of TV before VAT (or the original cost) be Rs 100
\(\therefore\) VAT = 12% of the original cost
= \(12\over100\) x Rs 100 = Rs 12
\(\therefore\)Cost of TV including VAT = Rs 100 +Rs12 = Rs 112
If price including VAT is Rs 112, then original cost = Rs 100
If price including VAT is Rs 89,600, then original
cost = \(100\over112\) x 89,600 = Rs 80,000

Rs 1653.60, Rs 1620 

We have, marked price = Rs 800
and selling price = Rs 760
∴ Discount = Marked Price - selling price
= Rs 800 - Rs 760 = Rs 40
Let the discount rate be x%.
Then, x% of marked price = 40
⇒ \(\frac{x}{100}\times 800=40\)
⇒ x = \(\frac{40\times 100}{800}\)
∴ x = 5%

2.25%

Given, cost price of a cycle = Rs 700
and overhead charges = Rs 50
Total cost price of a cycle = Cost price of a cycle + Overhead charges
= Rs (700 + 50) = Rs 750
Also, given profit in per cent = 5%
Now, profit = 5% of total cost price of a cycle
= 5% of Rs 750
\(=(\frac{5}{100}\times750)=(\frac{3750}{100})\)= Rs 37.50
∴ Selling price of a cycle = Total cost price of a cycle + Profit
= Rs (750 + 37.50) = Rs 787.50
Hence, the selling price of a cycle is Rs 787.50.

S.l. = 100 x 1 x (3 x 12) = 3600 paise
= Rs. 36

100 - 20 = 80
∵ If C.P. is 100, then S.P. = Rs. 80
∴ If C.P. is Rs. 500, then S.P.
= \(\frac { 80 }{ 500 } \times \)500 = Rs.400.

Number of students who like to watch
T.V. = 30% of 100 = \(\frac { 30 }{ 100 } \) x 100 = 30.

1 km = 1000 m
10 m : 1000 m or 10 : 1000 or 1 : 100.