A sample of 300 jellybeans was removed from a barrel of jellybeans. All
of the jellybeans in the barrel are one of four colors: red, orange,
green, and purple. For the sample, the number of jellybeans of each
color is shown in the table below.
Color
Number of jellybeans
red
75
, where T1 and T2 represent the time needed for hoses 1 and 2, respectively, to fill the pool on their own, and Tc
represents the time needed for hoses 1 and 2 to fill the pool working
together. If hose 1 alone can fill the pool in exactly 20 minutes and
hose 2 alone can fill the pool in exactly 60 minutes, how many minutes
will it take to fill the pool if both hoses work simultaneously?
(A) 3
(B) 10
(C) 15
(D) 18
(E) 40
Correct Answer: C
For a chemistry class, Sanjay is doing an experiment that involves
periodically heating a container of liquid. The graph below shows the
temperature of the liquid at different times during the experiment. What
is the average rate of change of temperature (in degrees Celsius per
minute) during the times in which Sanjay is applying heat to this
container?
