RATIOS & RATES
An aquarium has 14 angelfish and 18 seahorses.
Write the ratio of angelfish to seahorses in simplest form.
Answer
7:9
Determine whether the table represents a proportional relationship.
Minutes: 6 14 25 48
Points: 8 20 32 60
Answer: No
A model lighthouse uses a scale of 8 inches = 30 feet.
If the actual lighthouse is 210 feet tall, how tall is the model?
Answer
56 inches = 4⅔ feet
What is 65% of 175?
Answer
175(.065)
=113.75
David drove 350 miles last week and 415 miles this week.
Find the percent change.
Answer: difference/original
(415−350)/350
=18.57%
A 60-page magazine costs $1.20 to print.
What is the cost per page?
Answer: $0.02 per page
Which ratios form a proportion?
9/12 = 12/8?
12/32 = 8/20?
9/12 = 12/8
Find the scale factor from Figure A to Figure B.
Figure A: 14 units Figure B: 16 units
┌──────────────┐ ┌────────────┐
│ │ │ │ │
│ │ 8 units│ │ 7 units │
│ │ │ │ │
└──────────────┘ └────────────┘
8/7 = 0.875 OR 14/16 = 0.875
115.6 is what percent of 340?
Answer: percent x whole = part
p(340)=115.6
=115.6/340 = 0.34
=34%
Sugar usage dropped from 42.5 pounds to 26 pounds.
Find the percent change.
Answer
38.8% decrease
Write the ratio in simplest form:
52 inches to 1 foot
Answer
52 inches to 12 inches
= 13 to 3
Solve:
16/120 = 15/v
Answer
16v=1800
v=112.5
A mailbox is 4½ feet tall and casts a 6-foot shadow.
A Ferris wheel casts an 84-foot shadow.
How tall is the Ferris wheel?
Answer: 63 feet
A manicure costs $28 and a pedicure costs $35.
Add a 15% tip.
What is the total?
Answer: $72.45
Commission on a $28,400 sale at 5.8%.
Answer: $1,647.20
A salesperson earns 5.8% commission on a $28,400 car.
Find the commission.
Answer: $1,647.20
There were 341 runners in wave 1,
295 in wave 2,
316 in wave 3.
If 7 out of every 8 runners finished, how many did not finish?
Answer
119 runners did not finish
A lighthouse casts a 36-foot shadow.
A 21-foot streetlamp casts a smaller shadow.
Find the lighthouse height.
Answer: 126 feet
Movie popcorn increased from $3.50 to $4.75.
Find the percent increase.
Answer: 35.7% increase
Tyler borrowed $42,000 at 5% simple interest for 15 years.
How much did he pay back in interest?
Answer: I=prt
I=42,000(.05)(15)
$31,500
Which is the better deal?
Option A: 15 pens for $12.19
Option B: 6 pens for $4.74
Option B
$4.74 ÷ 6 = $0.79 each
$12.19 ÷ 15 ≈ $0.81 each
$500 DAILY DOUBLE!!!!
A recipe uses 2⅓ cups of milk for 16 cookies.
How much milk is needed for 24 cookies?
Answer
3.5 cups
DAILY DOUBLE:
Given similar figures, find x.
Small Figure Large Figure
15 21
/------\ /------\
/ \ / \
/ \ / \
/ \ / \
/ \ / \
/________________\ /________________\
12 x
Answer: x = 25
15/21 = 12/x
A laptop costs $209.
The store increases the price by 12%.
What is the new price?
Answer
209(.12) = 25.08 INCREASE
209 + 25.08 =
$234.08
Alice borrowed $16,700 at 9% for 10 years. What was the total amount she paid on the loan after 10 years?
Answer:
16,700(.09)(10) = 15,030
16,700 + 15,030 = $31,730