Answer:
45
Explanation:
360 / 8 = 45
Let a be the amount needed of 70% pure antifreeze, and let b be the amount needed of 95% pure antifreeze.
0.7a + 0.95b = 180 * 0.9 .........(1)
a + b = 180 .............................(2)
b = 180 - a ..............................(3)
Plugging the expression for b in equation (3) into equation (1), we get:
0.7a + 0.95(180 - a) = 162 ......(4)
Solving equation (4) gives the value a = 36, and plugging this value for a into equation (2) we get b = 144.
Amounts needed are therefore 36 gallons of 70% pure antifreeze and 144 gallons of 95% pure antifreeze.
Answer: her call lasted for 44 minutes
Step-by-step explanation:
Linda purchase a prepaid phone card for $30. This means that the credit on her card is $30.
Long distance calls cost $0.17 each. Linda use her card only to make a long distance call. Assuming she made a total of x minutes of long distance calls, the cost would be $0.17x. The amount remaining on her card will be
30 - 0.17x
if the remaining credit on her card is $22.52, the number of minutes,x that the call lasted will be
22.52 = 30 - 0.17x
0.17x = 30 - 22.52
0.17x = 7.48
x = 7.48/0.17 = 44
Step-by-step explanation:
The value of the expression 4b^2+11 when b=5 is
4×5^2+11
100+11
111
