Question

12. If the square of given number is negative then such number is called —
13. For
any real number x, the smallest integer greater than or equal to x is denoted by
14. If A=(a,b), then n(AXB) is equal to—.
15. If n(A)=27, n(B)=35 and n(AUB)=48, then n(ANB) is equal to —.
QUESTION NUMBERS 16 TO 20 ARE VERY SHORT ANSWER TYPE QUESTIONS.
16. Prove that n(n-1)(n-2)... (n-r+1) =n!/(n-r)!
17. Find the LCM of {6!,7!,8!).
18. Evaluate 100C98
19. Find the sum of the G.P :
1+3+9+27+ ....... to 7 term.
​

Answer 1

Least Common Multiple of 6,7,8 is 336

Answer 2

Answer:

18.

Step-by-step explanation:

100C98 = 100!/98!(100-98!)

=> 100!/98!*2!

=> 100*99*98! / 98!*2

=> 99*100/2

=> 99*50

=> 4950