Answer:
A: C = 2: 1
Explanation:
Please see the attached pictures for the full solution.
Further explanantion (2nd image):
The reason why the ratio of A: C is equal to the ratio if 2A: 2C is that the number of parts of A and C is equal, which is 2 parts. If I were to divide both 2A and 2C by 2 to find the ratio of A: C, I would obtain 15: 15/2. However, ratios are expressed as whole numbers and thus, we would multiply the whole ratio by 2 again and the answer would still be 30: 15. This ratio is not in the simplest form since both can be divided by 15. Thus, dividing both sides of the ratio by 15 will leave us with the final answer of
A: C= 2: 1.
☆ An alternative method is to simplify the ratio 3B: 2C at the beginning.
3B: 2C
= 36: 15
= 12: 5
Multiply the first ratio by 2 so 3B has 12 parts in both ratios:
2A: 3B
= 10: 12
Combining the 2 ratios together,
2A: 3B: 2C
= 10: 6: 5
2A: 2C
= 10: 5
= 2: 1
A: C= 2: 1