Answer: First Option is correct.
Step-by-step explanation:
Since we have given that
Number of hours Chance can wash the car = 2 hours
Number of hours Sandy can wash the car = 4 hours
Work done by Chance per hour is given by
Work done by Sandy per hour is given by
Work done by altogether per hour is given by
So, Number of hours they take if they together wash the car is given by
Hence, First Option is correct.
Hello there!
1. Okay. So 70% is positive, so it is a corresponding growth. 70% is 0.7 in decimal form. C and D are both eliminated, because that's too large. When something grows by 70%, that is less than double. 0.7 is not right either, because that's more of a decay than a growth. The only answer that makes sense id 1.70, because you are going up, and adding 1 to decimal form brings you to the decimal that when multiplied will bring you to the total. The answer is B: 1.70.
2. So, -75% is negative, so it is a decay factor. A is eliminated, because it makes no sense and B is out, because that represents growth, not decay. You lose 75% of the amount overtime compounded, but you still have 25% that remains. To find that amount, you would subtract that amount from 1 to get the decay. 1 - 0.75 is 0.25. The decay factor is 0.25. The answer is D: 0.25.
The answer is x=20. Hope this helps.
Since 
(density = mass/volume), we can get the mass/weight of the liquid by integrating the density 
over the interior of the tank. This is done with the integral
which is more readily computed in cylindrical coordinates as
