Which two ratios form a proportion?
02:3 and 4:12
02:3 and 6:12
02:3 and 12: 18
02:3 and 12:36

02:3 and 12:18

Step-by-step explanation:

A proportion is formed when the larger ratio can be simplified to equal the smaller ratio:

#1

02:3 and 4:12

Reducing the larger ratio: 4:12=1:3

Hence, not a proportion.

#2

02:3 and 6:12

Reducing the larger ratio: 6:12=1:2

Hence, not a proportion.

#3

02:3 and 12:18

Reducing the larger ratio: 12:18=2:3

Hence, they form a proportion.

#4

02:3 and 12:18

Reducing the larger ratio: 12:36=1:3

Hence, not a proportion.

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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