math games for grades 9 12

Question: Find the number of triangles that can be drawn through 12 distinct points, no three of which are collinear. Answer: To draw a triangle, we require three non-collinear points. Hence, the number of triangles that can be drawn is ..

Question: Convert the following into factorials: i) 5.6.7.8.9.10 ii) 4.6.8.10.12 Answer: i) ii) ..

Let a=first term, d = common difference, l=t n =last term, s = required sum. Then, Writing the series in the reverse order, Adding together the two series, ..

Question: How many words of different 4 letters can be formed out of 7 capital letters, 3 vowels and 8 consonants, if each word starts with a capital letter and contains at least one vowel? Answer: Any capital letter can be chosen as the first letter of each word. So there are 7 ways of..

Question: Twelve students are participating in a competition. In how many ways can the first 3 prizes be won? Answer: Number of students participating in the competition = 12 The number of ways in which the first three prizes can be won = P (12,3) = 12..

The matrices are identify matrices of order 2 and 3 respectivel..

Find the adjoint of the matrix. ..

are symmetric matric..