Aweight of 15 ounces stretches a spring 10 inches. a weight of 24 ounces stretches the same spring 16 inches. how many inches does the spring stretch per ounce of additional weight?

16-10 = 6 inches

24-15  = 9 ounces

it stretches 6 inches when 9 ounces are added

 divide 6 inches by 9 ounces

6 / 9 = 0.67 inches per ounce

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)