Posts

Featured Posts

Dictionary Rank of a Word | Permutations & Combinations

 PERMUTATIONS & COMBINATIONS Rank of the word or Dictionary order of the English words like COMPUTER, COLLEGE, SUCCESS, SOCCER, RAIN, FATHER, etc. Dictionary Rank of a Word Method of finding the Rank (Dictionary Order) of the word “R A I N” Given word: R A I N Total letters = 4 Letters in alphabetical order: A, I, N, R No. of words formed starting with A = 3! = 6 No. of words formed starting with I = 3! = 6 No. of words formed starting with N = 3! = 6 After N there is R which is required R ----- Required A ---- Required I ---- Required N ---- Required RAIN ----- 1 word RANK OF THE WORD “R A I N” A….. = 3! = 6 I……. = 3! = 6 N….. = 3! = 6 R…A…I…N = 1 word 6 6 6 1 TOTAL 19 Rank of “R A I N” is 19 Method of finding the Rank (Dictionary Order) of the word  “F A T H E R” Given word is :  "F A T H E R" In alphabetical order: A, E, F, H, R, T Words beginning with A = 5! = 120 Words b

Theorems on Quadrilaterals Ch-8 Class-IX

Image
  Theorems on Parallelograms Ch-8 Class-IX Explanation of all theorems on Parallelograms chapter 8 class IX, Theorem 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 8.10, Mid point theorem and its converse. All theorems of chapter 8 class IX. Theorem 8.1: Prove that a diagonal of a parallelogram divides it into two congruent triangles. Given: In Parallelogram ABCD, AC is the diagonal To Prove:  △ACD ≌ △ABC Proof: In △ACD and △ABC,  ∠1 = ∠2  .........   (Alternate angles ∠3 = ∠4  ..........  (Alternate interior angles AC = AC ........   (Common Sides ⇒ By ASA  ≌ rule   △ACD ≌ △ABC   Theorem 8.2: In a parallelogram, opposite sides are equal. Given: ABCD is a parallelogram To Prove : AB = CD and BC = AD Proof:  In △ ACD and △ ABC,  ∠ 1 = ∠ 2  .........   (Alternate angles ∠ 3 = ∠ 4  ..........  (Alternate interior angles AC = AC ........   (Common Sides ⇒ By ASA  ≌ rule   △ ACD ≌ △ ABC ⇒ AB = CD and BC = AD  …..  By CPCT Theorem

Breaking News

Followers

Popular Post on this Blog

Lesson Plan Maths Class 10 | For Mathematics Teacher

Lesson Plan Math Class X (Ch-13) | Surface Area and Volume

Lesson Plan Math Class X (Ch-8) | Trigonometry

SUBSCRIBE FOR NEW POSTS