If one third of t is 7 than t is equal to 21
D. After 150 minutes, the 5 cent one is more.
Hope this helps!
Answer:
Rate of change
C per meter.
Step-by-step explanation:
Given,

Then,

Change of temperature at the point say,
along the direction say,
is,
![\Big[uT_{x_2}+vT_{y_2}+wT_{z_2}\Big]_{(x,y,z)}](https://tex.z-dn.net/?f=%5CBig%5BuT_%7Bx_2%7D%2BvT_%7By_2%7D%2BwT_%7Bz_2%7D%5CBig%5D_%7B%28x%2Cy%2Cz%29%7D)

=
Hence the rate of change of temperature is
C per meter.