Commerce (English Medium) Class 11 - CBSE Question Bank Solutions

If (a + ib) (c + id) (e + if) (g + ih) = A + iB, then show that (a² + b²) (c² + d²) (e² + f²) (g² + h²) = A² + B².

If `((1+i)/(1-i))^m` = 1, then find the least positive integral value of m.

Evaluate 8!

Evaluate 4! – 3!

Is 3! + 4! = 7!?

Compute `(8!)/(6! xx 2!)`

if `1/(6!) + 1/(7!) = x/(8!)`, find x

Evaluate `(n!)/((n-r)!)` when  n = 6, r = 2 

Evaluate `(n!)/((n-r)!)`, when n = 9, r = 5

How many 3-digit even numbers can be made using the digits 1, 2, 3, 4, 6, 7, if no digit is repeated?

Find the number of 4-digit numbers that can be formed using the digits 1, 2, 3, 4, 5 if no digit is repeated. How many of these will be even?

From a committee of 8 persons, in how many ways can we choose a chairman and a vice chairman assuming one person cannot hold more than one position?

Find n if ^{n – 1}P₃ : ⁿP₄ = 1 : 9

Find r if `""^5P_r = 2^6 P_(r-1)`

Find r if `""^5P_r = 2^6 P_(r-1)`

Find r if `""^5P_r = ""^6P_(r-1)`

How many words, with or without meaning, can be formed using all the letters of the word EQUATION, using each letter exactly once?