The histogram shows final exam scores, and the table shows letter grades for each range of scores. A passing grade is 60% or higher. A 90–100%
B 80–90%
C 70–80%
D 60–70%
Which statement is supported by the data in the histogram?
A. Twenty students received As and Bs.
B. Forty students received scores between 40% and 60%.
C. Most students received As and Bs.
D. Most students passed the final exam.

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.