Một hộp đựng 10 quả cầu gồm: 2 quả màu đỏ, 3 quả màu vàng và 5 quả màu xanh. Chọn ngẫu nhiên từ hộp đó ra 4 quả cầu. Tính xác suất chọn được 2 quả màu
xanh.

Solve the system of equations. y= 2x y= x^2 - 15

Miranda is braiding her hair.then she will attach beads to the braid.she wants 1_3 of the beads to be red.if the greatest number of beads that will fit on the braid is 12,what other fractions could represent the part of the beads that are red?

Alice is paying her bill at a restaurant. but tax on the cost of a male is 5%. she decides to leave a tip 20% of the cost of the meal plus the tax