The seven-digit number 1113a8b can be divided by 4, 5, and 9 what is the sum of the digits a and b?

4

Step-by-step explanation:

This seven-digit number can be divided by 4, 5 and 9.

This means that 4, 5 and 9 are ALL factors.

Find the least common multiply (LCM) of 4, 5 and 9.

Multiples of 4: 4 , 8 , 12 , 16 , 20

Multiples of 5: 5 , 10 , 15 , 20

Find a multiple of 9 that is also a multiple of 20. All multiples of 20 have the factors 4 and 5.

9 X 20 = 180

The seven-digit number must be a multiple of 180 to have the factor 4, 5 and 9. You can find the multiples of 180 until the number looks like 1113A8B, but there are better methods.

All multiples of 180 end in the digit "0". Therefore B = 0.

1113A80

Since 9 is one of the factors, the rules for a number divisible for 3 apply. (9 is a multiple of 3).

You know that a number is divisible by 3 when its digits add to a number divisible by 3.

Find the sum of the digits:

1+1+1+3+A+8+0 = A + 14

A + 14 must be divisible by 3.

Therefore, A has to be either 1, 4, or 7.

If A = 1

1113180 ÷ 180 = 6184.333

If A = 4

1113480÷ 180= 6186

If A = 7

1113780 ÷ 180 = 6187.7

A = 4 because that number is divisible by 180.

Add A = 4 and B = 0.

A + B

= 4 + 0

= 4

The sum of digits A and B is 4.

x=17

step-by-step explanation:

solve 3x-24=x+10

then that makes it 2x=34 because you subtract an x from both sides to get rid of the one on the right, and then you add 24 to both sides to get rid of the 24 on the left

divide by both sides by 2 to get your answer so that you can get your answer