Which ratios form a proportion? 3/15, 12/55 8/24, 12/35 5/18, 25/90 4/11, 16/25 what ratio forms a proportion with 9/15? 6/10 16/21 36/50 45/70

1. C)  5/18, 25/90

2.  A) 6/10

Step-by-step explanation: 1) We need to find the ratios those makes a proportion:

Let us check given options one by one.

3/15, 12/55  

Converting them into simplest fractions.

3÷3/15÷3 = 1/5

12/55 can't be reduce more.

1/5 ≠ 12/55

So, 3/15, 12/55  don't form a proportion.

8/24, 12/35

Converting them into simplest fractions.

8÷8/24÷8 = 1/3

12/35 can't be reduce more.

8/24 ≠ 12/35

So, 8/24, 12/35 don't form a proportion.

So, 5/18, 25/90 form a proportion.

4/11, 16/25

Converting them into simplest fractions.

4/11 and 16/25 both can't be reduce more.

4/11≠16/25

So, 4/11, 16/25 don't form a proportion.

Let us reduce 9/15 into simplest fraction.

Now, let us convert each and every option in simplest fractions.

16÷1/21÷1 = 16/21

36÷2/50÷2 = 18/25

45÷5/70÷5 = 9/14

We can see 6/10 gives lowest fraction 3/5 as 9/15 gives.

Therefore, 6/10 form a proportion with 9/15.