maths
posted by cutie !!! help me please .
1. a man sells a tv for rupees 3450and makes a profit of 15% . he sells a second tv set at a loss of 10%.if on the whole he neither gains nor loses , find the cost price of the second tv.
2.a man sells two tables at the same price. on one he makes a profit of 10% and on the other he suffers a loss of 10%. find his gain or loss percent on the whole transaction.
3. a makes an article for rupees 120 and sells it to b at a profit of 25%. b sells it to c and sell it for rupees198 making a profit of 10% . what profit percent did b make?
4. the costs of manufacture of an article is made up of materials , labours and overheads in ratio 4:3:2. if the cost of labour is rupees 45 , find the total cost of an article. find the profit%, if the article is sold for rupees180.
5. an article is sold at a profit of 10%. had it been sold for rupees 20more , 12% profit would have been made. find the cost price of the article.

I'll do one, then you can show har far you get on the others. Just put the words into symbols and solve the resultant equation(s).
#1.
If the two TVs cost x and y, then
1.15x = 3450
x + y = 1.15x + .90y
So, x = 3450/1.15 = 3000
.1y = 34503000 = 450
y = 4500
The two TVs cost 3000 and 4500
check:
90% of 4500 = 4050
cost: 3000+4500 = 7500
income: 3450+4050 = 7500 
O