Questions in mathematics

Questions in mathematics

[Free] You place a cup of $210^{\circ} F$ coffee on a table in a room that is $68^{\circ} F$, and 10 minutes later, it is $200^{\circ} F$. Approximately how long will it be before the coffee is $180^{\circ} F$ ? Use Newton's law of cooling: $T(t)=T_A+\left(T_o-T_A\right) e^{-k t}$ A. 1 hour B. 15 minutes C. 33 minutes D. 45 minutes

[Free] Arc AB is $\frac{1}{6}$ of the circumference of a circle. What is the radian measure of the central angle? A. $\frac{\pi}{6}$ B. $\frac{\pi}{3}$ C. $\frac{2 \pi}{3}$ D. $\frac{5 \pi}{6}$

[Free] Two identical cones are inscribed in a cylinder. Which equation represents the volume of each cone? A. [tex]$V=\frac{\pi r^2 H}{2}$[/tex] B. [tex]$V=\frac{\pi r^2 H}{4}$[/tex] C. [tex]$V=\frac{\pi r^2 H}{3}$[/tex] D. [tex]$V=\frac{\pi r^2 H}{6}$[/tex]

[Free] What is the $x$-coordinate of the point that divides the directed line segment from J to K into a ratio of 2.5? $x=\left(\frac{m}{m+n}\right)\left(x_2-x_1\right)+x_1$

[Free] Drag each tile to the correct box. Not all tiles will be used. Drag the explanations used to solve the given equation in the correct sequence. [tex]5^{(6 x-9)}=125[/tex] * subtract 9 from each side * divide each side by 6 * add 9 to each side * rewrite 125 as a power of 5 * equate the exponents of the equation * divide each side by 5

[Free] Clayton transferred a balance of $4125 to a new credit card at the beginning of the year. The card offered an introductory APR of 7.9% for the first 5 months and a standard APR of 25.7% thereafter. If the card compounds interest monthly, which of these expressions represents Clayton's balance at the end of the year? (Assume that Clayton will make no payments or new purchases during the year, and ignore any possible late payment fees.) A. ($4125)(1+\frac{0.079}{5})^{12}(1+\frac{0.257}{7})^{12} B. ($4125)(1+\frac{0.079}{12})^5(1+\frac{0.257}{12})^7 C. ($4125)(1+\frac{0.079}{5})^5(1+\frac{0.257}{7})^7 D. ($4125)(1+\frac{0.079}{12})^{12}(1+\frac{0.257}{12})^{12}

[Free] 3 \times 8-8 \div 2-6

[Free] $\lim _{x \rightarrow \frac{\pi}{2}} \frac{1-\sin x}{\cos x}$

[Free] Solve the system for x and y. [tex] \begin{array}{l} -8 x-y=-43 \\ 8 x-5 y=-71 \end{array} [/tex] A. (3,19) B. (-2,11) C. (2,27) D. (4,11)

[Free] Amy and Aaron each have a card with a number written on it. Amy's number is $x$ and Aaron's number is $y$. (a) If Amy multiplies her number by 6 and subtracts it by 10, the result is the same as 2 times Aaron's number. Show that $3x - y = 5$