A train having a length of 500 m passes through a tunnel of 1000 m in 1 minute. What is the speed of the train in Km/hr?

A and B can do a piece of work together in 15 days while A alone can do it in 25 days. They start working together but B leaves 5 days before the completion of the work. For how many days did A and B work together?

Read the given question and decide which of the following statements is/are sufficient to answer the question.
What is the number of students in the class?
Statements:
1) The class contains $$10^{th}$$ class students.
2) The class contains 6 girls and 8 boys.

Read the given statement(s) and conclusions carefully and select which of the conclusions logically follow( s) from the statement( s ).
Statements:
I. All gadgets are electronics.
II. All electronics are chips.
Conclusions:
1. All gadgets are chips.
2. Some chips are electronics.

Read the statements and answer the question based on it.
Statements:
1. Some mammals are extinct and some are critically endangered.
2. All dinosaurs are extinct.
3. Some reptiles are critically endangered and some are already extinct.
Which option logically follows the given statements?