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Write one digit on each side of 15 to make a four digit multiple of 15. How many different solutions does this problem have? The possible solutions are.....

Respuesta :

Answer:

1155, 3150, 4155, 6150, 7155, 9150

There are 6.

Step-by-step explanation:

First, the number would have to end in 0 or 5.

So if we try 1150 it does not divide but 1155 is a multiple.

Also the number would also be divisible by 3 so the sum of its digits would also have to be  divisible by 3 so this rules out 2 being the first digit .

3150 is a multiple but not  3155

4155 is a multiple.

5xxx cannot be ,  6150 is , so is 7155 ,

8xxx cannot be . 9150 is.

Answer:

There are 6 solutions

Step-by-step explanation:

All multiples of 15 are multiples of 5, then all finish in 0 or 5. Therefore, the four digits possibilities are:  1150 , 1155 , 2150 , 2155 , 3150 , 3155 , 4150 , 4155 , 5150 , 5155 , 6150 , 6155 , 7150 , 7155 , 8150 , 8155 , 9150  and 9155 . Only 1155 ,  3150 , 4155 , 6150 , 7155  and 9150  are multiples of 15.