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I am a 3 digit number divisible by 7 but not 2 the sum of my digits is 4 what number am I
Reqd no. is 9 -digits.. available digits are 1 2 3 4 5.. Numbers which are divisible by 4 can be determined by the last two digits.. from the given combinations,, the numbers div by 4 are 12, 24, 32, 44, 52 so.. the number's last two digits can be any of the above 5. Hence, we have to calculate the combinations for the first 7 digits.. Ans: (5C1)^7 * 5 ie 5^8 = 390625
3 digits numbers: from 100 to 999 The first number greater than 100 and divisible by 7 is 105 The last number lower than 999 and divisible by 7 is is 987 (987-105)/7=126 intervals of 7-length In fact 127 as numbers are to be counted, not intervals
Not evenly. An easy way to tell is that its digits add up to 7, a number which is not divisible by 3.
1- Any number is divisible by 1. 2- Any even number is divisible by 2. 3- If its digits add up to a number divisible by 3, the whole number is divisible by 3. 4- If the last two digits are divisible by 4, the whole number is divisible by 4. 5- If it ends in 5 or 0, the whole number is divisible by 5. 6- If it's even and also divisible by 3, the whole number is divisible by 6. 7- There is no rule for 7. 8- If the last three digits are divisible by 8, the whole number is divisible by 8. 9- If its digits add up to a number divisible by 9, the whole number is divisible by 9. 10- If it ends in 0, the whole number is divisible by 10.
If the number is even, it's divisible by 2. If the sum of the digits is a multiple of 3, the whole number is divisible by 3. If the last two digits are a multiple of 4, the whole number is divisible by 4. If the last digit is a 0 or a 5, the whole number is divisible by 5. If the number is even and divisible by 3, it's divisible by 6. If the last digit doubled subtracted from the rest is a multiple of 7, the whole number is divisible by 7. If the last three digits are a multiple of 8, the whole number is divisible by 8. If the sum of the digits is a multiple of 9, the whole number is divisible by 9. If the number ends in 0, it's divisible by 10.
Nope - in order for a number to be divisible by 9, the sum of its digits must also be divisible by 9. In this case, the digits 2+4+2+7=15.
48. Assuming no digit can be used more than once, the two digit numbers divisible by 4 are: 16, 36, 48, 56, 64, 68, 84, 96 8 of them. For any number to be divisible by 4, only the last two digits need be divisible by 4; so for three digit numbers, each of the two digit numbers above can be preceded by any of the remaining 5 digits and still be divisible by 4. → 5 x 8 = 40 three digit numbers are divisible by 4 → 40 + 8 = 48 two or three digit numbers made up of the digits {1, 3, 4, 5, 6, 8, 9} are divisible by 4. If repeats are allowed, there are an extra 2 two digit numbers (44 and 88) and each of the two digit numbers can be preceded by any of the 7 digits, making a total of 7 x 10 + 10 = 80 two and three digits numbers divisible by 4 make up of digits from the given set.
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7800 is divisible by:2 - because it is 2 if it is even3 - the sum of its digits (7+8+0+0 = 15) is a multiple of 3 :4 - the last two digits is a multiple of 45 - it ends or 5 with 06 - it is divisible by 2 and 38 - the last three digits (800) is multiple of 810 - it ends with 0
No, because if you add the three digits together, you get 7 which isn't divisible by 3