Answer:
(b) 67
Step-by-step explanation:
A solution to the differential equation describing the temperature according to Newton's Law of Cooling could be written as ...
T = (final temp) + (initial difference)×(decay factor)^t
where the decay factor is the fraction of change during 1 unit of time period t.
__
Here, the initial difference of 100-25 = 75 degrees decays to 90-25 = 65 degrees in 1 minute. So, the units of t are minutes, the decay factor is 65/75, the initial difference is 75 degrees, and the final temperature is 25 degrees. That lets us write the equation as ...
T = 25 +75(65/75)^t
Then for t=4, the temperature is ...
T = 25 +75(13/15)^4 ≈ 67.3 . . . . degrees
After 4 minutes the temperature of the coffee is about 67 degrees.
Answer:
Step-by-step explanation:
Amount paid for first 100 watches = (65% of 80) *100
Amount paid for next 50 watches = (55% of 80) * 50
Remaining watches = 280 -(100+ 55)
= 280 - 155 = 125
Amount paid for 125 watches = (45% of 80) *125
Amount received by the watch maker = 5200 + 2200 + 4500
= £ 11900
Answer:
11
Step-by-step explanation:
y-1=10
Any figure that crosses equal sign, the operational sign changes.
y=10+1
y= 11
Answer:
The above mentioned qualities go under the category of abilities.
Step-by-step explanation:
Lily does a self-inventory to find out theat she has knowledge of Excel , proficiency in bookkeeping and training in customer service .
Ability is used to refer a person's native aptitude in a specific field.
Ability can also be trained and honed and can be made better with practice.
All of Lily's qualities mentioned come under the same above mentioned specifications. All her talents can be trained and can be bettered.
Hence her qualities come under the category of abilities.
