Which of these are SI Units?

Question

i need help in finding out which of the following groups are all SI Units and if they are not can u explain why thanks in advance

1. cm, s, kg, lb, µm

2. fm, ns, kg, mm, µs

3. km, s, kg, µm, ft

4. mm, µm, g, s, in.

5. none of these

Answer 1

non of them are, so 5.

1,3,4 is obvious

2) m is the SI unit not fm or mm, s is the SI unit not ns, or µs

Answer 2

2 is

in 1, lb (pound) is not SI

in 3, ft (feet) is not SI

in 4, in (inches) is not SI

Answer 3

5. None of these

1. NOT SI Unit: lb

2. Not SI Unit:

3. NOT SI Unit: ft

4. NOT SI Unit: in

Answer 4

The answer is 2.

lb (pound) is not an SI unit.

ft (foot) is not an SI unit.

in (inch) is not an SI unit.

m (meter) is the SI unit of distance.

kg (kilogram) is the SI unit of mass.

s (second) is the SI unit of time.

The prefixes represented in the question are c (centi- 1/100), k (kilo- 1000), µ (micro- 1/1000000), m(milli- 1/1000).

Answer 5

2 is correct if fm means femtometers

1, 3 and 4 have feet, lbs, and inches which are imperial units so they are wrong

Answer 6

2