This is 6C2
= 6!
-------- = 6*5 / 2*1 = 15
2! 4!
Answer:

Step-by-step explanation:
we require 2 equations with the repeating digits placed after the decimal point.
let x = 0.888.. (1) ← multiply both sides by 10
10x = 8.888.. (2)
subtract (1) from (2) thus eliminating the repeating digits
9x = 8 ( divide both sides by 9 )
x = 
Grams
At least that is what we use in Mexico and in most Latin-American countries