Lunch Costs and Book Relationships

The video tutorial covers four math problems. Problem 120 involves calculating the total number of books owned by three people in terms of a variable d. Problem 121 calculates the total number of games played in a league where each team plays every other team once. Problem 122 involves solving an equation using a defined operation theta. Problem 123 calculates the average price per person for a lunch, excluding gratuity.

If David has d books, which is 3 times as many as Jeff, how many books does Jeff have in terms of d?

• 3d

• d/3

• d/2

• 2d

If Paula has twice as many books as David, how many books does Paula have in terms of d?

• d/2

• 2d

• d

• 3d

What is the total number of books owned by David, Jeff, and Paula in terms of d?

• 3d

• 10d/3

• d

• 5d

In a league with 8 teams where each team plays every other team exactly once, how many total games are played?

• 32

• 64

• 56

• 28

If a theta b is defined as (a - b) / (a + b), what is the result when a theta c equals zero?

• a = -b

• a = b

• a = 0

• a = c

What condition must be met for the operation a theta b to be defined?

• a = 0

• a = b

• b = 0

• a ≠ -b

If the total cost of lunch for 15 people is $207 including a 15% gratuity, what is the total cost before gratuity?

• $200

• $150

• $207

• $180

What is the average price per person for the lunch, excluding gratuity?

• $14

• $10

• $15

• $12

How do you calculate the price before gratuity if the total cost including gratuity is known?

• Multiply by 1.15

• Divide by 1.15

• Subtract 15%

• Add 15%

If the price before gratuity is $180, what is the total cost including a 15% gratuity?

• $180

• $207

• $210

• $200