An approximate number, that can be calculated mentally, is by using the rule of 72: Divide 72 by the interest in % to give the number of years needed to double the money.
In this case, the approximate number of years
n= 72/4=18 years (approximately)
Precise value by compound interest formula:
2P=P*(1.04)^n
=>
1.04^n=2
take logs on both sides
nlog(1.04)=log(2)
n=log(2)/log(1.04)=17.673 years
For

the function is undefined.

So, the limit doesn't exist.
Answer:
-62/23 degrees per hour
Step-by-step explanation:
Do this by dividing the total change in temperature (-15 1/2 degrees) by the total elapsed time (5 3/4 hrs):
-31/2 degrees -62/4 degrees Note: convert 31/2 to 62/4
--------------------- = ------------------------ = -62/23 degrees per hour
23/4 hrs 23/4 hrs
The amount of paint used is <u>8.4 litres</u>.
<h3>
EXPLANATION</h3>
To work this out, you need to<em> times 1.2 by 7</em>, to get the answer of <u>8.4 litres</u>.
Hope this helps!