math help please??

Question

could you show me the steps on how to figure these out?

19: A lawn-and-garden dealer wants to make a new blend of grass seed by using 200 pounds of $0.45 per pound seed and some $0.65 per pound seed. How much of the $0.65 seed does the dealer need to make a $0.55 per pound blend? 100 lbs
180 lbs
200 lbs
220 lbs

10: Peanuts sell for $3.00 per pound. Cashews sell for $6.00 per pound. How many pounds of cashews should be mixed with 12 pounds of peanuts to obtain a mixture that sells for $4.20 per pound?
5
6
7
8

11: 6kg of inferior quality tea are mixed with 3kg of high quality tea which costs $2.00 per kilogram more than the inferior tea. The total price of the mixture is $24.00. What is the price of the inferior tea?
$2 per kg.
$3 per kg.
$5 per kg.
$7 per kg.

The nut shop sells peanuts for $15 per kg and cashews for $10 per kg. How many kg of cashews would be in the mix in order to get 20 kg of a mixture worth $12 per kg?
4 kg
8 kg
10 kg
12 kg

Answer 1

These are all the same type of problem. I'll do the first one.

19: A lawn-and-garden dealer wants to make a new blend of grass seed by using 200 pounds of $0.45 per pound seed and some $0.65 per pound seed. How much of the $0.65 seed does the dealer need to make a $0.55 per pound blend?

Let
x = amount of $0.65 seed used

200*0.45 + .65x = (200 + x)*.55
90 + .65x = 110 + .55x
.10x = 20
x = 200

You need 200 lbs of $0.65 seed to make the mixture.

Answer 2

ooh, fun...I'll give it a shot...

19) well, $0.55 is the average of (midpoint between) $0.45 and $0.65 so you need the same amount of each, mixed evenly, to get the average cost of $0.55

11) ok...x is the cost of the lower cost...
3(2+x) + 6(x) = 24
[3(2+x) + 6(x)] / 3 = 24/3
2+x + 2(x) = 8
x + 2(x) = 8-2
3(x) = 6
x = 2
$2 for the inferior one, $4 for the other

sorry, but the time i get the others, i'm sure someone else will have already answered. if this is your homework, you really should be doing it yourself anyway....

Answer 3

10.

12(3.00)+x(6.00) = (12+x)(4.20)
36+6x=50.40+4.20x
1.80x=14.40
x=8

Answer 4

im glad im not in school anymore lol good luck