There are 90 students in a speech contest. Yesterday 2/3 of them gave their speeches. Today,1/3 of the remaining gave their speeches. How many students still haven't given their speeches?

The number of the students is 20.

Step-by-step explanation:

Total number of students in the speech contest = 90

Number of students that gave their speeches yesterday = of 90

                                                  = x 90

                                                  = 60

Number of remaining students who have not given their speeches after the first day = 90 - 60

                                                 = 30

Number of students that gave their speeches today = of 30

                                                  = x 30

                                                  = 10

Number of students that have not given their speeches = 30 - 10

                                                    = 20

Thus, 20 students have not given their speeches.

good bye

step-by-step explanation:

b. astronomers