x is your starting running time. 1/10 of a minute is 6 seconds, so you can do x - 6(6). 6 times 6 = 36, so your answer is x - 36 seconds. 36 seconds.
We are usually concerned with one reaction. That is, the production of one specific set of products from a specific set of reactants.
The number of values of c/d would be the number of possible ways that a and b could recombine to form different pairs of products c and d. (You might get different reactions at different temperatures, for example. Or, you might get different pars of ions.)
Usually, the number of values of c/d is one (1). (Of course, if you simply swap what you're calling "c" and "d", then you double that number, whatever it is.)
A. True. This is because distances are preserved and kept the same.
B. True. Moving any point to it's corresponding image is having you travel 8 units.
C. True. Corresponding angles are congruent.
D. False. This is not always true so in general it's false.
The final answer is choice D
For this problem, I think there is no need for the details of 12 inches width and 4 inches length. This is because an equation is already given. It was clearly specified that A as a function of θ represents the area of the opening. Then, we are asked to find exactly that: the area of opening. Moreover, the value of θ was also given. Therefore, I am quite sure that the initial details given are for the purpose of red herring only.
So, all we have to do is substitute θ=45° to the function given.
A = 16 sin 45° ⋅ (cos 45° + 1)
The angle 45° is a special angle in trigonometry. So, it would be easy to remember trigonometric functions of this angle. Sine of 45° is equal to √2/2 while cosine of 45° is also √2/2.
A = 16(√2/2) ⋅ (√2/2 + 1)
A = 8+8√2
A = 19.31 square inches
