Which ratios form a proportion?
4/9, 12/25
3/7, 18/42
5/11, 20/45
5/8, 15/25
Which ratios form a proportion with 18/30?
20/35
50/90
36/48
60/100
Which proportion has cross products of 5 x 24 and 8 x 15?
5/8 x 15/24
5/24 x 8/15
8/24 x 15/5
15/8 x 5/24
1. B
2. D
3. A
You're welcome to all
TY minoru
I agree with Minoru.
To determine if two ratios form a proportion, you need to check if their cross products are equal. Cross products are obtained by multiplying the numerator of one ratio by the denominator of the other ratio. Let's go through each set of ratios to see which ones form a proportion:
1) 4/9 and 12/25:
Cross products: 4 x 25 = 100 and 9 x 12 = 108
Since the cross products are not equal (100 ≠ 108), these ratios do not form a proportion.
2) 3/7 and 18/42:
Cross products: 3 x 42 = 126 and 7 x 18 = 126
In this case, the cross products are equal (126 = 126), which means these ratios form a proportion.
3) 5/11 and 20/45:
Cross products: 5 x 45 = 225 and 11 x 20 = 220
Since the cross products are not equal (225 ≠ 220), these ratios do not form a proportion.
4) 5/8 and 15/25:
Cross products: 5 x 25 = 125 and 8 x 15 = 120
Again, the cross products are not equal (125 ≠ 120), so these ratios do not form a proportion.
From the given options, only the ratios 3/7 and 18/42 form a proportion.
Now let's move on to the next question:
To determine if a ratio forms a proportion with 18/30, we need to find ratios whose cross products are equal to 18 x 30 = 540.
1) 20/35:
Cross product: 20 x 30 = 600
Since the cross product is not equal to 540 (600 ≠ 540), this ratio does not form a proportion with 18/30.
2) 50/90:
Cross product: 50 x 30 = 1500
Again, the cross product is not equal to 540 (1500 ≠ 540), so this ratio does not form a proportion with 18/30.
3) 36/48:
Cross product: 36 x 30 = 1080
Once again, the cross product is not equal to 540 (1080 ≠ 540), so this ratio does not form a proportion with 18/30.
4) 60/100:
Cross product: 60 x 30 = 1800
Since the cross product is not equal to 540 (1800 ≠ 540), this ratio does not form a proportion with 18/30.
From the given options, none of the ratios form a proportion with 18/30.
Finally, let's determine which proportion has cross products of 5 x 24 and 8 x 15.
1) 5/8 x 15/24:
Cross product: 5 x 24 = 120 and 8 x 15 = 120
In this case, the cross products are equal (120 = 120), which means this proportion has the desired cross products.
2) 5/24 x 8/15:
Cross product: 5 x 15 = 75 and 24 x 8 = 192
Since the cross products are not equal (75 ≠ 192), this proportion does not have the desired cross products.
3) 8/24 x 15/5:
Cross product: 8 x 5 = 40 and 24 x 15 = 360
Once again, the cross products are not equal (40 ≠ 360), so this proportion does not have the desired cross products.
4) 15/8 x 5/24:
Cross product: 15 x 24 = 360 and 8 x 5 = 40
The cross products are not equal (360 ≠ 40), so this proportion does not have the desired cross products.
Therefore, the proportion 5/8 x 15/24 is the one with cross products of 5 x 24 and 8 x 15.