4.3 – Real World Problems: Ratios
Objective…
Part A: Draw models to solve problems involving ratios
1)
Megan prepares a fruit punch using apple juice & orange juice in the ratio 4 : 3.
Draw it…
a. If the total volume of fruit punch is 630 milliliters, find the volume of apple
juice Megan uses.
b. If Megan uses 520 milliliters of apple juice to make the fruit punch, find the
volume of orange juice she uses.
2)
Draw it…
A box contains baseball and football cards. The number of baseball cards to
the number of football cards is in the ratio 5 : 1.
a. If the total number of cards is 1,380 find the number of each type of cards.
b. Suppose the number of baseball cards is 950, find the number of football
cards.
Part B: Draw models to solve problems involving ratios of three quantities
4.3 – Real World Problems: Ratios
1)
Draw it…
2)
Draw it…
3)
Draw it…
Jenny prepares a ceramic glaze mixture of feldspar, red iron oxide, and silica in
the ratio 5 : 2 : 3. The mass of the mixture is 1200 grams. Find the mass of
each ingredient used to prepare the mixture.
A school raised $18,000 at a charity event. The money raised was shared
among three charities, A, B, and C, in the ratio 1 : 2 : 3. How much money did
each charity receive?
The number of coins collected by Xavier, Yohann, and Zachary is in the ratio
2 : 5 : 8. Yohann collected 85 coins.
a. Find the number of coins Zachary collected.
b. Find the number of coins collected by the three boys altogether.
4.3 – Real World Problems: Ratios
Part C: Draw models to solve problems involving two sets of ratios
1)
The ratio of the number of CDs Brad has to the number of CDs Keith has is
2 : 3. The ratio of the number of CDs Keith has to the number of CDs Simone
has is 6 : 11. Brad has 24 CDs. How many CDs do Keith and Simone have?
altogether?
Equivalent Ratios…
Bar Model…
2)
At Stacey’s middle school, students either ride bikes to school, walk, or take a
bus. The ratio of the number of students who ride bikes to the number who
walks is 3 : 4. The ratio of the number of students who walk to the number who
take a bus is 12 : 7. There are 560 students in all.
Equivalent Ratios…
Bar Model…
a. Find the number of students who ride bikes to school.
b. Find the number of students who walk to school.
c. Find the number of students who take a bus to school.
4.3 – Real World Problems: Ratios
Part D: Draw models to solve before and after problems
1)
Before…
Sam had some US and foreign stamps. The ratio of the number of US stamps
to the number of foreign stamps was 3 : 4. He bought 21 more US stamps and
the ratio became 9 : 8.
After…
a. How many foreign stamps did Sam have?
b. How many US stamps did Sam have in the end?
2)
Before…
Claire keeps some green and red plates in a cabinet. The ratio of the number of
green plates to the number of red plates is 2 : 1. She adds 18 more red plates
in the cabinet and the ratio becomes 4 : 5.
After…
a. How many green plates are there in the cabinet?
b. How many red plates are there in the cabinet in the end?
4.3 – Real World Problems: Ratios