Ten percent less than twice the total number of students present in the science class yesterday have attended class today. If there were 70 students in the class yesterday and 30 students are absent today, calculate the number of students registered for the course. Let's think first. Chain of thought:
Twice the number of students present in the science class yesterday is 70 * 2 = 140. Ten percent less than twice the number of students present in the class yesterday means there are 10 / 100 * 140 = 14 fewer students than twice the number present yesterday. The number of students present in the science class today is 140 - 14 = 126. If the total number of registered students for the course who are absent today is 30, a full class of the science course has 126 + 30 = 156 students.
Therefore, the answer is 156.