The two digit number is 43.
If flipped around, the number is 34, which is 9 less than 43. 4 + 3 = 7.
Hope this helps!
From the setup of the problem, the "length of the top of the bookcase, measured along the attic ceiling" will be the hypotenuse of a right triangle, the length "AB". We have both the angle between AB and AC and the length of AC (3.24 meters), so we can use trigonometric identities.
The cosine of the 40 degree angle between AB and AC is equivalent to the length of AC divided by the length of AB. Equivalently, we have:

where "h", the hypotenuse, is the length we want. Rearranging the formula to solve for h we have that

which is 4.2295... meters. Converting to centimeters (multiplying by 100) we have that h = 422.95... centimeters, or if we round the value, h = 423 centimeters.
Answer:
197.2 million
Step-by-step explanation:
The appropriate exponential equation for the population is ...
p(t) = 172.0e^(0.019t)
Then we can compute for t=7.2:
p(7.2) = 172.0e^(0.019·7.2) ≈ 172.0·1.146599 ≈ 197.2
7.2 minutes from now, the population will be about 197.2 million.
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For continuous growth (or continuous compounding), the exponential formula is ...
f(t) = (value at t=0)×e^(rt)
where r is the growth rate in one unit of time, and t is the number of time periods.
Answer:
It should be Volume of water
It is $6 more now than before...maybe you were looking for percent increase?
%change=100(final-initial)/initial
%change=100(10-4)/4=150% increase