The number of different signals which can be give from 6 flags of different colours taking one or more at a time is _________

(a)

1958

(b)

1956

(c)

16

(d)

64

Number of all four digit numbers having different digits formed of the digits 1, 2, 3, 4 and 5 and divisible by 4 is _________

(a)

24

(b)

30

(c)

125

(d)

100

If 10ⁿ + 3 \(\times\) 4ⁿ⁺²+\(\lambda \) is divisible by 9 for all n \(\in \)N, then the least positive integral value of \(\lambda \) is _________

(a)

5

(b)

3

(c)

7

(d)

1

If ⁿP_r=k x ^n-1P_r-1 what is k:

(a)

r

(b)

n

(c)

n+1

(d)

r+1

The number of rectangles than can be formed on a chess board is  _________

(a)

⁹C₂

(b)

⁹C₂ \(\times\) ⁹C₂

(c)

204

(d)

224