Advertisements
Advertisements
Question
Count the number of three-digit numbers which can be formed from the digits 2, 4, 6, 8 if repetitions of digits is allowed
Solution
Number of digits given = 4 (2, 4, 6, 8)
So the unit place can be filled in 4 ways,
10’s place can be filled in 4 ways and 100’s place can be filled in 4 ways
∴ The unit place, 10’s place and 100’s place together can be filled
(i.e) So the Number of 3 digit numbers = 4 × 4 × 4 = 64 ways
APPEARS IN
RELATED QUESTIONS
How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that repetition of the digits is not allowed?
How many 4-letter code can be formed using the first 10 letters of the English alphabet, if no letter can be repeated?
Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?
How many numbers between 100 and 1000 have the digit 7 exactly once?
A teacher wants to select the class monitor in a class of 30 boys and 20 girls. In how many ways can the monitor be selected if the monitor must be a girl or a boy?
How many three-digit numbers can be formed from the digits 0, 1, 3, 5, 6 if repetitions of digits are allowed?
How many numbers between 100 and 1000 have 4 in the units place?
How many five-digit numbers formed using the digit 0, 1, 2, 3, 4, 5 are divisible by 5 if digits are not repeated?
How many words can be formed by writing letters in the word CROWN in different order?
Given four flags of different colours, how many different signals can be generated if each signal requires the use of three flags, one below the other?
Count the number of three-digit numbers which can be formed from the digits 2, 4, 6, 8 if repetitions of digits is not allowed
How many three-digit numbers are there with 3 in the unit place?
with repetition
In how many ways 10 pigeons can be placed in 3 different pigeon holes?
Find the value of 6!
Evaluate `("n"!)/("r"!("n" - "r")!)` when n = 6, r = 2
Evaluate `("n"!)/("r"!("n" - "r")!)` when for any n with r = 2
Choose the correct alternative:
In an examination there are three multiple choice questions and each question has 5 choices. Number of ways in which a student can fail to get all answer correct i
How many numbers are there between 99 and 1000 having 7 in the units place?
In a steamer there are stalls for 12 animals, and there are horses, cows and calves (not less than 12 each) ready to be shipped. They can be loaded in 312 ways.
