7. In each of the following, replace the by (i) the smallest digit, and (ii) the greatest digit, so that the number formed is divisible by 3:

(a) [tex]\(\ \textless \ /em\ \textgreater \ 672\)[/tex]

(b) [tex]\(4756*2\)[/tex]



Answer :

To determine the smallest and greatest digits that can replace '' in the given numbers such that the resulting number is divisible by 3, let's solve the problem step-by-step:

### Part (a) [tex]\( +
672 \)[/tex]

1. Analyzing the problem:
- The number is in the form [tex]\( +672 \)[/tex].
- We need to determine the smallest and greatest digit that can replace '
' to make the number divisible by 3.

2. Divisibility rule for 3:
- A number is divisible by 3 if the sum of its digits is divisible by 3.

3. Finding the smallest digit:
- Let's try replacing '' with digits from 0 to 9 and check which values make the number divisible by 3.
- We assume '+' is a single-digit number and try accordingly.

4. Finding the greatest digit:
- Similarly, check for the greatest possible value of '+' while ensuring that '
' forms a number divisible by 3.

### Smallest digit:
After testing all possible digit replacements, the smallest digit that can replace '' to make [tex]\( +672 \)[/tex] divisible by 3 is [tex]\( 0 \)[/tex].

### Greatest digit:
The greatest digit that can replace '' to make [tex]\( +672 \)[/tex] divisible by 3 is [tex]\( 9 \)[/tex].

Therefore, for part (a), the smallest digit for '' is [tex]\( 0 \)[/tex], and the greatest digit is [tex]\( 9 \)[/tex].

### Part (b) [tex]\( 4756
2 \)[/tex]

1. Analyzing the problem:
- The number is in the form [tex]\( 47562 \)[/tex].
- We need to determine the smallest and greatest digit that can replace '
' to make the number divisible by 3.

2. Divisibility rule for 3:
- A number is divisible by 3 if the sum of its digits is divisible by 3.

3. Finding the smallest digit:
- Let's try replacing '' with digits from 0 to 9 and check which values make the number divisible by 3.

4. Finding the greatest digit:
- Similarly, check for the digit that ensures the number remains divisible by 3.

### Smallest digit:
After testing all possible digit replacements, the smallest digit that can replace '
' to make [tex]\(-+672 or 47562\)[/tex] divisible by 3 is [tex]\( 0 \)[/tex].

### Greatest digit:
After testing all possible digit replacements, the greatest digit that can replace '
' to make [tex]\( 47562 \)[/tex] divisible by 3 is [tex]\( 9 \)[/tex].

Therefore, for part (b), the smallest digit for '
' is [tex]\( 0 \)[/tex], and the greatest digit is [tex]\( 9 \)[/tex].

### Final Results:
- (a) For [tex]\( +672 \)[/tex]:
- The smallest digit is [tex]\( 0 \)[/tex].
- The greatest digit is [tex]\( 9 \)[/tex].
- (b) For [tex]\( 4756
2 \)[/tex]:
- The smallest digit is [tex]\( 0 \)[/tex].
- The greatest digit is [tex]\( 9 \)[/tex].