grade 4 math tutoring

Question: A committee of 6 is chosen from 10 men and 7 women so as to contain atleast 3 men and 2 women. In how many different ways can this be done, if two particular women refuse to serve on the same committee? Answer: Let the two ladies who refuse to work on the same committee be d..

Question: Prove that n!(n + 2) = n! + (n + 1)!. Answer: L.H.S = n!(n + 2) = n![(n+1)+1] ..

Consider the arrangement In this arrangement, there are two rows and four columns. The number 3 lies in the 2 n d row and 4 t h column. Each number has a fixed position. Matrix A has 2 rows and 3 columns and is thus of order 2 x 3. Matrix B has 3 rows and 2 columns and is thus o..

Question: The sides AB, BC, CA of a triangle ABC have 3, 4 and 5 interior points respectively on them. Find the number of triangles that can be drawn using these points as vertices. Answer: The points 3+4+5=12 points lie in a plane. To construct a triangle, we requir..

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

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 or last place, they for..

Question: At an election, three wards of a town are canvassed by 4, 5 and 8 men respectively. If 20 men volunteer, in how many ways can they be allotted to the different wards? Answer: Let the three wards be labelled as A, B and C respectively. Let us select 4 men fo..

Row Matrix - 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: There are three different rings to be worn in 5 fingers with at most one in each finger. In how many ways can this be done? Answer: For the first ring, there are 4 options as one finger cannot have more than one ring. The remaining two fingers will have 3 and 2 optio..