Question 423877
1) One investment pays 4% and another pays 11%. If equal amounts are invested in each account, the combined interest income for one year is $1,125.00. How much is invested at each rate?

4%--------$x
11%-------$x
4x+11x=1125*100
15x=112500
/15
x=$7300 in each

2)A turtle leaves Gila Bend heading north at 50mph. Two hours later a second turtle leaves Gila Bend heading north at 75mph. How long will it take the second turtle to overtake the first?

Turtle 1	 50	mph			
Turtle 2	 75	mph			
Difference in time= 02:00		
Turtle 1will have covered 100 miles before Turtle 2 starts
					
catch up distance=		100	miles		
catch up speed =		75	-50	mph	
catch up speed =		25	mph		
					
Catchup time = catchup distance/catch up speed					
catch up time=		100	/	25	
catch up time=		4	hours		



3) Two boats leave port at the same time, one heading east at 60 knots per hour and the other heading west at 50 knots per hour. How long will it take them to be 715 miles apart?

Add up speeds since they are going in opposite directions
50+60 =110 knots
distance = 715 miles
Time = 715/110
=6.5 hours

4)A store manager mixes candy worth 90 cents per pound with gumdrops worth $1.50 per pound to make 20 pounds of a mixture worth $1.20 per pound. How many pounds of each kind of candy must he use?

0.9----------------	x
1.5----------------	20-x
1.20----------------	20

0.9x+1.5	(20-x)=1.2*	20
0.9x+30-	1.5x=24		
0.9x-1.5	x=24-30		
-0.6x-=	-6							
/-0.6								
x=10 pounds of $ 0.90		
10 pounds of $1.50		
		

5) A store sells regular coffee for $4 per pound and a gourmet coffee for $7 per pound. To get rid of 40 pounds of the gourmet, the shopkeeper plans to make gourmet blend to sell for $5 a pound. How many pounds of regular coffee should be used? 

$7----------------	40
$4----------------	x
$5----------------	40+x
...
7*40+4*x	=5(40+x)
280+4x=200+5x					
4x-5x=200-280					
-1x=-80		
/-1									
x=80 pounds of $4