There are
90
students in a speech contest. Yesterday,
2/5
of them gave their speeches. Today,
2/3
of the remaining students gave their speeches. How many students still haven't given their speeches?
First off, 3/5 of 90 is 54. Therefore, 54 students who did not give their speeches yesterday. Secondly, 1/3 of 54 is 18. Therefore, 18 students did not give their speeches today.