In a bag, 12 marbles are blue. this is 80% of the marbles. how many marbles are there in total?

15

Step-by-step explanation:

given:

80% > 12 marbles

1% > 12/80 marbles

hence

100% > (12/18) x 100 = 15 marbles

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.  

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)