Solving Problems Involving Solving Problems Involving Equivalent RatiosEquivalent Ratios

Lesson 3 (3Lesson 3 (3rdrd 6 Weeks) 6 Weeks)

TEKS 6.2CTEKS 6.2C

RatioRatio

Comparison of two Comparison of two quantitiesquantities

7 to 10 = 7:10 = 7/10 = 0.77 to 10 = 7:10 = 7/10 = 0.7

ProportionProportion

Two Two equivalentequivalent ratios or rates ratios or rates

25 15

6=

These ratios are equivalent. (proportional)

Use this method to solve Use this method to solve problems involving ratios and problems involving ratios and

ratesrates EX: The volley ball team has a 3:2 ratio of EX: The volley ball team has a 3:2 ratio of

girls to boys. If there are 12 boys on the girls to boys. If there are 12 boys on the team, how many girls are on the team?team, how many girls are on the team?

1.Write the original ratio as a 1.Write the original ratio as a fractionfraction in a in a ratio table.ratio table.

3

2

EX: The volley ball team has a 3:2 ratio of girls to boys. If EX: The volley ball team has a 3:2 ratio of girls to boys. If there are 12 boys on the team, how many girls are on there are 12 boys on the team, how many girls are on the team?the team?

2. 2. LabelLabel the the termsterms..

3. Write an 3. Write an equivalentequivalent ratio with 12 boys ratio with 12 boys and unknown number of girls. Use a and unknown number of girls. Use a variablevariable for the unknown number of for the unknown number of girls.girls.

4. 4. SolveSolve for the for the variablevariable..

3

2

girls

boys 12

g

x 6

x 618

Example 2:Example 2:

Sue made 7 out of every 10 free throws Sue made 7 out of every 10 free throws during the last 6 games of the basketball during the last 6 games of the basketball season. If she made 21 free throws, how season. If she made 21 free throws, how many did she attempt?many did she attempt?

7

10

made

attempted a

21

x 3

x 3

30