Để A55B chia hết cho 36 thì 5B chia hết cho 4 và A + 5 + 5 + B chia hết cho 9
⇒ B = 2 hoặc B = 6
*) B = 2
⇒ A + 5 + 5 + 2 = A + 12 chia hết cho 9
⇒ A = 6
*) B = 6
⇒ A + 5 + 5 + 6 = A + 16 chia hết cho 9
⇒ A = 2
⇒ A = 6; B = 2
Hoặc A = 2; B = 6
Vậy A + B = 2 + 6 = 6 + 2 = 8
Câu 9:
The average mass of a group of children is 47kg. If of the number of children are girls and their average mass is 39kg. Find the average mass of the boys.
Answer: The average mass of the boys is kg
Câu 10:
A 6-digit number begins with the digit 8. The number is divisible by 9 and all digits of the number are different. What is the possible smallest value of this number?
Answer:
A 6 digit number begins with the digit 8.The number with divisible by 9 and all digits of the number are different.What is the possible smallest value of this number?
The sum of the digits of a ten-digit number is epual to 9.What is the product of the digits of this number?
The sum of two numbers is the greatest 4 – digit number and their ratio is 1:2. The smaller number is ?
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 (for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 ( for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out?
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 (for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out?
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 (for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out?
