Atest consists of 10 true-false questions. suppose a student answers the questions by flipping a coin, that is, if head means true and tail means false. let x denote the number correctly answered questions. (hint: it might be if you use relevant r commands to obtain the values of pmf and cdf.) (a) give the expected value and variance of x. (b) find the probability the student will answer correctly exactly 5 of the questions. (c) find the probability the student will answer correctly at most 5 of the questions. use the cdf to answer this quesition. (d) let y = 10 − x. in words, what does y represent? (e) use the cdf to find p(2 ≤ y ≤ 5).

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.