Sara has six necklaces, but her mother will only allow her to wear two at a time. how many different combinations of two necklaces can sara wear?

15 different combinations

Step-by-step explanation:

Sara has six necklaces, but her mother will allow her to wear two at a time.

So we calculate different combinations of two necklaces by this formula:

Where n = 6 and r = 2

Now put the values

= 15 combinations

Sara can wear 15 different combinations of two necklaces.

111

step-by-step explanation:

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²