5 digit combination padlock

Asked by maham237 @ 03/01/2021 in Mathematics viewed by 150 People

A 5-digit combination lock with digits 0-9 can be opened only if a correct combination of digits is chosen. Find the probability of guessing the correct combination if:
A. no digit is repeated

B. digits can repeat and zero is not one of the digits in the combination

(Can this be done in fraction form? Thanks!)

Answered by maham237 @ 03/01/2021

A. 5 digit code with digits from 0-9 with no repetition.

Choices for 1st digit=10, and choices for successive digits are 9,8,7,6.

Probability of guessing it correctly on first try is

1/(10*9*8*7*6) = 1/30240

B. If zero is not in the combinations, then the domain of digits is 1-9, or 9 choices. Digits can repeat means every digit in the code has 9 choices.

Number of arrangements = 9^5 = 59049

Probability of guessing at first try = 1/59049

The smallest 5 digit number

Asked by admin @ 24/08/2021 in Math viewed by 304 persons

Question 5 Write the smallest 5-digit number and express it in the form of its prime factors. Class 6 - Math - Playing with Numbers Page 62

What is the smallest 5 digit number divisible by 99

Asked by admin @ 03/08/2021 in Math viewed by 320 persons

Find the smallest 5 digit number which is exactly divisible by 99

How many 5 digit numbers are there in all

Asked by admin @ 10/08/2021 in Math viewed by 312 persons

How many 5 digit numbers are there in all

The smallest 7 digit number ending in 5 is

Asked by admin @ 17/08/2021 in Math viewed by 291 persons

The smallest 7 digit number ending in 5 is_______

How many 3 digit numbers are divisible by 5

Asked by admin @ 13/08/2021 in Math viewed by 328 persons

How many 3 digit numbers are divisible by 5 solution?

The predecessor of the smallest 5 digit number is

Asked by admin @ 11/08/2021 in Math viewed by 284 persons

● The predecessor of the smallest 5 digit number is _________.

How many two digit numbers are divisible by 5

Asked by admin @ 11/08/2021 in Math viewed by 316 persons

How many two digit numbers are divisible by 5

How many three digit numbers are divisible by 5

Asked by admin @ 11/08/2021 in Math viewed by 384 persons

How many 3 digit numbers are divisible by 5 solution?

How many 5 digit telephone numbers can be constructed

Asked by admin @ 13/08/2021 in Math viewed by 367 persons

How many 5-digit telephone numbers can be constructed using the digits 0 to 9 if each number starts with 67 and no digit appears more than once?

The largest 5 digit number exactly divisible by 91 is

Asked by admin @ 04/08/2021 in Math viewed by 274 persons

The largest 5 digit number exactly divisible by 91 is:

Find the greatest perfect square of 5 digit number

Asked by admin @ 20/08/2021 in Math viewed by 327 persons

Find the greatest 5 digit number which is a perfect square.find iys square root.

How to divide 4 digit numbers by 4 digit numbers

Asked by admin @ 26/11/2021 in Mathematics viewed by 265 persons

Write and solve a division problem that divides a 4-digit number by a 2-digit number.How did you estimate the first digit of the quotient

How to multiply 3 digit numbers by 2 digit numbers

Asked by admin @ 09/11/2021 in Mathematics viewed by 371 persons

When you multiply a 3 digit number by a 2 digit number, what is the greatest number of digits the product can have? Explain

The phone number area code must be a 3 digit

Asked by admin @ 05/11/2021 in Mathematics viewed by 356 persons

Phone numbers consist of a three-digit area code followed by seven digits. If the area code must have a 0 or 1 for the second digit, and neither the area …