22,23,24-evaluating the options:
read the question carefully. we have to choose values from same class. so first divide the classes. when temperature falls below 18 switch is turned off. this forms a class (as shown below). when the temperature is more than 21, the switch is turned on. for values between 18 to 21, no action is taken. this also forms a class as shown below.
class i: less than 18 (switch turned off)
class ii: 18 to 21
class iii: above 21 (switch turned on)
from the given options select the option which has values from only one particular class. option a values are not in one class, so eliminate. option b values are not in one class, so eliminate. option c values are in one class. option d values are not in one class, so eliminate. (please note that the question does not talk about valid or invalid classes. it is only about values in same class)
the answer is c
Answer Anonymously
Copy Link
