Okie, so percent decrease is the amount loss divided by the original number and multiplied by 100 to find the percent. This is because you are finding the amount loss in terms of the total amount - percent basically.
The amount loss : 4 feet
4 feet/ 12 feet = .3333 (ratio of how much cut) multiply by 100 --> 33.3% decrease. From 12 feet to 8 feet is a 33.3 % decrease. I hope this helps :-)
Your answer would be 2 and 1/4 because when you divide 9 and 4 you get that.
Answer:
a letter in a math problem
Box
Too
Box
3m+
Msg ape shape
Answer:
a). 59.049°C
b). 2.1179 seconds
Step-by-step explanation:
Expression representing the final temperature after decrease in temperature of the metal from 100°C to T°C is,
T = 
where x = duration of cooling
a). Temperature when x = 5 seconds
T = 100(0.9)⁵
= 59.049
≈ 59.049°C
b). If the temperature of the metal decreases from 100°C to 80°C
Which means for T = 80°C we have to calculate the duration of cooling 'x' seconds
80 = 
0.8 = 
By taking log on both the sides
log(0.8) =log[
]
-0.09691 = x[log(0.9)]
-0.09691 = -0.045757x
x = 
x = 2.1179
x ≈ 2.1179 seconds