Inverted nine

In the hotel,, Inverted nine" each hotel room number is divisible by 6. How many rooms we can count with three-digit number registered by digits 1,8,7,4,9?

Correct result:

n =  18

Solution:

$$\begin{gathered} n_1=114 \\ {n}_2=714 \\ {n}_3=414 \\ {n}_4=174 \\ {n}_5=774 \\ {n}_6=474 \\ {n}_7=894 \\ {n}_8=144 \\ {n}_9=744 \\ {n}_{10}=444 \\ {n}_{11}=984 \\ {n}_{12}=918 \\ {n}_{13}=978 \\ {n}_{14}=198 \\ {n}_{15}=798 \\ {n}_{16}=498 \\ {n}_{17}=948 \\ {n}_{18}=888 \\ n=18 \end{gathered}$$

Try another example

Showing 0 comments:

Next similar math problems:

• Three digits number
  From the numbers 1, 2, 3, 4, 5 create three-digit numbers that digits not repeat and number is divisible by 2. How many numbers are there?
• The Hotel
  The Holiday Hotel has the same number of rooms on each floor. Rooms are numbered with natural numerals sequentially from the first floor, no number is omitted, and each room has a different number. Three tourists arrived at the hotel. The first one was in
• Digits
  How many five-digit numbers can be written from numbers 0.3,4, 5, 7 that is divided by 10 and if digits can be repeated.
• Numbers
  How many different 3 digit natural numbers in which no digit is repeated, can be composed from digits 0,1,2?
• Three-digit numbers
  We have digits 0,1,4,7 that cannot be repeated. How many three-digit numbers can we write from them? You can help by listing all the numbers.
• Combinations
  How many different combinations of two-digit number divisible by 4 arises from the digits 3, 5 and 7?
• Digits
  How many natural numbers greater than 4000 which are formed from the numbers 0,1,3,7,9 with the figures not repeated, B) How many will the number of natural numbers less than 4000 and the numbers can be repeated?
• Three-digit numbers
  How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
• Dd 2-digit numbers
  Find all odd 2-digit natural numbers compiled from digits 1; 3; 4; 6; 8 if the digits are not repeated.
• Six-digit primes
  Find all six-digit prime numbers that contain each one of digits 1,2,4,5,7 and 8 just once. How many are they?
• By six
  From the digits 1,2,3,4 we create the long integer number 123412341234. .. .. , which will have 962 digits. Is this number divisible by 6?
• How many 4
  How many 4 digit numbers that are divisible by 10 can be formed from the numbers 3, 5, 7, 8, 9, 0 such that no number repeats?
• How many
  How many double-digit numbers greater than 30 we can create from digits 0, 1, 2, 3, 4, 5? Numbers cannot be repeated in a two-digit number.
• Phone numbers
  How many 7-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
• Three digits number
  How many are three-digit integers such that in they no digit repeats?
• PIN code
  PIN on Michael credit card is a four-digit number. Michael told this to his friend: • It is a prime number - that is, a number greater than 1, which is only divisible by number one and by itself. • The first digit is larger than the second. • The second d
• Number 4
  Kamila wrote all natural numbers from 1 to 400 inclusive. How many times did she write the number 4?