math series grade 4

From a class of 32 students, 4 are to be chosen for a competition. In how many ways can this be don..

Circular Permutations - When things are arranged in places along a line with first and last place, they form a linear permutation. So far we have dealt only with linear permutations. When things are arranged in places along a closed curve or a circle, in which any place may be regarded as the first..

A matrix having only one row is called a row-matrix. For example: A[1 3 2 -2] is a row matrix of order 1 x 4..

Question: From a class of 32 students, 4 are to be chosen for a competition. In how many ways can this be done? Answer: We are to select 4 students from 32. This selection can done in ..

Question: How many six digits telephone numbers can be made if each number starts with 45 and no digit appears more than once? Answer: The first two places are reserved for 4 and 5. The remaining 8 digits can be arranged in P(8,4) = 8.7.6.5 = 1680 way..

We are to select 4 students from 32. This selection can done i..

Solve the system of linear equations. x +2y + 3z = 6 2x + 4y + z = 7 3x + 2y + 9z = 14 using Cramer's rul..

= (14 - 12) - (7 - 3) + (4 - 2) = 2 - 4 + 2 = 0 The system may have infinite number of solutions or no solution. Put x = k in (1) and (2) and solve y + z = 6 - k 2y + 3z = 14 - k. Solving the above two equations, we have z = k + 2 and y = 4 - 2k When x = k, subs..

Question: A candidate is required to answer 6 out of 10 questions, which are divided into two groups, each containing 5 questions, and he is not permitted to attempt more than 4 from each group. In how many ways can he make his choice? Answer: ..

Equality of Matrices - Two matrices are said to be equal if they have the same order and their corresponding elements are equal. e.g., then a = 1, b = 2, c = 3, d = 4, e = 5 and f = ..