In a class of 10, there are 2 students who forgot their lunch. if the teacher chooses 2 students, what is the probability that both of them forgot their lunch?

At the beginning, the chances that the teacher will choose a student who has forgotten his lunch are 2/10, or 1/5.

If the teacher now chooses another student from the remaining 9 students, the chances of his choosing a student who has forgotten his lunch are 1/9, since one of the forgetful students has already been removed from the original group of 10 students, and there are only 9 in the group remaining.

The probability that both students forgot lunch is (1/5)(1/9), or 1/45.

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)