# GMAT 700+ Math Question 16

#### Word Problem | Number Properties & Linear Equations

The given question is GMAT 700+ Math problem solving question combining concepts in number properties and linear equations. The question is a GMAT hard math word problem.

Question 16: A movie hall sold tickets to one of its shows in two denominations, $11 and$7. A fourth of all those who bought a ticket also spent $4 each on refreshments at the movie hall. If the total collections from tickets and refreshments for the show was$124, how many $7 tickets were sold? Note: The number of$11 tickets sold is different from the number of $7 tickets sold. 1. 14 2. 11 3. 2 4. 8 5. 5 ## Get to Q51 in GMAT Quant #### Online GMAT Course @ INR 3500 ### Video Explanation ## GMAT Live Online Classes #### Start Tue, Oct 12, 2021 ### Explanatory Answer | GMAT Word Problem #### Step 1: Assign Variables | Frame Equations Let ‘x’ and ‘y’ be the number of tickets sold at$11 and $7 respectively. Then, total number of tickets sold = x + y Collection by selling 'x'$11 tickets = 11x
Collection by selling 'y' $7 tickets = 7y Total collection by selling (x + y) tickets = 11x + 7y A fourth of all those who bought a ticket also spent$4 each on refreshments at the movie hall.
i.e., $$frac{1}{4}$$x + y) spent $4 on refreshments. ∴ Collections from sale of refreshments = $$frac{1}{4}$$x + y) × 4 = (x + y) Total collection from tickets and refreshments =$124
i.e., 11x + 7y + (x + y) = 124
Or 12x + 8y = 124
Divide the equation by 4: 3x + 2y = 31

#### Step 2: Solve 3x + 2y = 31 for x and y using these 2 facts

Fact 1: x and y are positive integers.
Fact 2: $$frac{1}{4}$$x + y) is an integer because a fourth of total tickets sold should be an integer. i.e., (x + y) should be a multiple of 4.

Let us list down the different possibilities that satisfy the equation and fact 1

x y 3x + 2Y x + y
9 2 27 + 4 = 31 11
7 5 21 + 10 = 31 12
5 8 15 + 16 = 31 13
3 11 9 + 22 = 31 14
1 14 3 + 28 = 31 15

Of all the different positive integer values of x and y that satisfy the equation, the only combination (x, y) = (7, 5) is divisible by 4

So, the movie hall sold five \$7 tickets.

#### GMAT Online CourseTry it free!

Register in 2 easy steps and
Start learning in 5 minutes!

#### GMAT Live Online Classes

Next Batch Oct 12, 2021

Next Batch
after Lockdown

#### GMAT Coaching in Chennai

Sign up for a Free Demo of our GMAT Classes in Chennai

##### Where is Wizako located?

Wizako - GMAT, GRE, SAT Prep
An Ascent Education Initiative
14B/1 Dr Thirumurthy Nagar 1st Street
Nungambakkam
Chennai 600 034. India

##### How to reach Wizako?

Phone: (91) 44 4500 8484
Mobile: (91) 95000 48484
WhatsApp: WhatsApp Now
Email: learn@wizako.com