Math miscellaneousHard
Question
The number of five digit numbers that contains digit 7 exactly once is if digits may be repeated)
Options
A.(41) (93)
B.(37)(93)
C.(7) (94)
D.(41)(94)
Solution
-
∴ if 7 fill in
first place
= 32 × 93 if 7 can be
fill in any last 4
94 + (32 × 93) = 41 × 93 places
∴ if 7 fill infirst place
= 32 × 93 if 7 can befill in any last 4
94 + (32 × 93) = 41 × 93 places
Create a free account to view solution
View Solution FreeMore Math miscellaneous Questions
If (10)9 + 2(11)1 (10)8 + 3(11)2 (10)7+ ... + 10(11)9 = k(10)9, then k is equal to...For r = 0, 1, ....., 10, let Ar, Br and Cr denote, respectively, the coefficient of xr in the expansions of (1 + x)10, (...Six cards and six envelopes are numbered 1, 2, 3, 4, 5, 6 and cards are to be placed in envelopes so that each envelope ...f′(x) and F(x) = If f′′(x) = - f(x) and g(x) = f′(x) and F(x) = and given that F(5) = 5, then F(...If f(x) = xg{x(1 - x)}dx and I2 = g{x(1 - x)}dx then the value of is...