Final answer:
To find the fourth digit of the number, divide the given number by 35 and check the remainder. If the remainder is 15, the fourth digit is 5.
Step-by-step explanation:
To find the fourth digit of the number, we need to understand how division with remainder works. When a number is divided by another number and has a remainder, we can write it as a division equation: 155 / 35 = 4 with a remainder of 15. This means that the divisor (35) goes into the dividend (155) four times, with a remainder of 15.
Since the first three digits of the number are given as 155, we need to find the fourth digit. To do this, we can divide the given number by 35 and see what the remainder is. If the remainder is 15, it means that the fourth digit is 5, because when we divide a number by 35, the remainder can only be a number between 0 and 34. So, the fourth digit of the number is 5.