3n+6b=72,
3n=72-6b
n=24-2b and we are also told that:
4n+5b=66 substituting in n found above into this equation gives
4(24-2b)+5b=66
96-8b+5b=66
-3b=-30
b=10 grams, and since from earlier we saw that n=24-2b
n=24-2(10)
n=24-20
n=4 grams
So the combined mass of one bold and one nut is:
10+4=14 grams
