Question

Урок начинается в 15:30 длится полтора часа во сколько он кончается

Answer 1

Полтора это 1 ч 30 минут значит 
15:30+1:30 = 17:00

Answer 2

Calculating Lesson End Time

To calculate the end time of the lesson that starts at 15:30 and lasts for one and a half hours, we can simply add 1.5 hours to the start time.

Start Time: 15:30 Duration: 1.5 hours

Calculation

The lesson will end at 17:00.

This information is based on the standard calculation of adding the duration to the start time