Ratio and Proportions Definition RATIO is a comparison
- Slides: 7
Ratio and Proportions
Definition RATIO is a comparison between two different things EXAMPLE: Suppose there are thirty-five people, fifteen of whom are men, what is the ratio of WOMEN TO MEN? – the ratio of women to men: 20 to 15 – NOT 15 to 20 – the order is IMPORTANT! IMPORTANT 9/29/2020 www. numberbender. com 2
Examples • There are 16 ducks and 9 geese in a certain park. Express the ratio of ducks to geese in all three formats. 16 : 9 16 / 9 16 to 9 • There are 18 black marbles, 11 blue marbles, and 12 brown marbles. What is the ratio of black marbles to blue marbles 18: 11 9/29/2020 18 / 11 www. numberbender. com 18 to 11 3
Solving Proportions • There are 2 cats and 3 dogs in the store. Suppose there are 12 cats in the store, how many dogs are there? Cat 2 : : Dog 3 12 X 2 = 3 12 X There are 18 dogs in the store 9/29/2020 www. numberbender. com 2 X = (3)(12) 2 X = 2 36 2 X = 18 4
Solving Proportions • If Jill has $15, and Jack has $5, then Jill has 30 more than Jack. How much money does Jack have? Jill 15 : : Jack 5 30 X 15 = 5 30 X Jack has $10 is his pocket. 9/29/2020 www. numberbender. com 15 X = (30)(5) 15 X 150 = 15 15 X = 10 5
More Practice 2 8 4 6 P : 20 : M = 6 P = 5 5 6 9/29/2020 M 9 : Z 9 www. numberbender. com 7 5 B : 18 6
Classwork x = 6 9/29/2020 x = 9 x = 16 www. numberbender. com x = 6 x = 14 x = 8 x = 6 7
