Ineed with 1-3 (it's for physical science)

1: 0.00196g/mL or 0.00196 grams per milliliter

2: the answer is 1 g/cm^3

3. 5g/mL

2142 divided by 7
7 will not go into 2 so u choose 21 goes in 3
3 times 7 is 21 that goes under 21 subtract
0 bring down 4...7 won't go into 4 so 0 goes above 4 next to 3...bring down 2 now u have 42...7 goes into 42 6 times...6 goes by 0 making number on top 306...6 times 7 is 42 which goes below 42 subtract leaving zero
answer is 306