Example on discrete mathematics, Mathematics

Assignment Help:

Suppose that at some future time every telephone in the world is assigned a number that contains a country code, 1 to 3 digits long, that is, of the form X, XX , XXX or followed by a ten-digit telephone number of the form NXX-NXX-XXXX. A telephone number consists of ten digits, which are split into a three-digit area code, a three-digit office code, and a four-digit station code. Because of signaling considerations, there are certain restrictions on some of these digits.

To specify the allowable format, let denote a digit that can take any of the values 0 through 9 and let denote a digit that can take any of the values 2 through 9.

How many different telephone numbers would be available worldwide under this numbering plan?


Related Discussions:- Example on discrete mathematics

Calculus, What is the slope of the line tangent to f(x)=3-2 ln(2x^2+4) at t...

What is the slope of the line tangent to f(x)=3-2 ln(2x^2+4) at the point (4, f(4))

Seqence and seies, If the M-th term of an Ap is n andn-th term M.find the p...

If the M-th term of an Ap is n andn-th term M.find the p-th term

Average, A boy covered half of distance at 20km/hr and rest at 40kmlhr. cal...

A boy covered half of distance at 20km/hr and rest at 40kmlhr. calculate his average speed.

Diffrentiation, y=f(a^x)   and f(sinx)=lnx find dy/dx Solution) dy/dx...

y=f(a^x)   and f(sinx)=lnx find dy/dx Solution) dy/dx = (a^x)(lnx)f''(a^x), .........(1) but f(sinx) = lnx implies f(x) = ln(arcsinx) hence f''(x) = (1/arcsinx) (1/ ( ( 1-x

What is a negative number, Q. What is a Negative Number? Ans. Neg...

Q. What is a Negative Number? Ans. Negative numbers  are very important in mathematics. We say that positive and negative numbers are  opposites  of one another. Here

Product moment coefficient, Product Moment Coefficient This gives an i...

Product Moment Coefficient This gives an indication of the strength of the linear relationship among two variables. Note that this formula can be rearranged to have di

Curve tracing, how to curve trace? and how to know whether the equation is ...

how to curve trace? and how to know whether the equation is a circle or parabola, hyperbola ellipse?

What is the integratin of 1/sin2x?, ∫1/sin2x dx = ∫cosec2x dx = 1/2 log[cos...

∫1/sin2x dx = ∫cosec2x dx = 1/2 log[cosec2x - cot2x] + c = 1/2 log[tan x] + c Detailed derivation of ∫cosec x dx = ∫cosec x(cosec x - cot x)/(cosec x - cot x) dx = ∫(cosec 2 x

What are real numbers, The hole set of irrational and rational numbers is t...

The hole set of irrational and rational numbers is the set of real numbers and is representing by R. Thus, the real numbers can also be describe in terms of position of a point on

Pattern, 1,5,14,30,55 find the next three numbers and the rule

1,5,14,30,55 find the next three numbers and the rule

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd