Probability with permutations and combinations There are 10 students in a class: 7 boys and 3 girls.
If the teacher picks a group of 4 at random, what is the probability that everyone in the group is a boy?

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

Someone me what is the area of this figure? 18m 18m 8m 16m

Tim has obtained a 3/27 balloon mortgage. after the initial period, he decided to refinance the balloon payment with a new 30-year mortgage. how many years will he be paying for his mortgage in total?