# Instructional Videos

### TJ SIS Math Problem 2020

A popular road in California is famous for its steepness and turns. It has been filmed for many car chases. In 1920 the builder decreased the slope from 27% to 14% to fit a 12-15% highway requirement.

What is the difference from the length of the old road and the new road if the height of the hill is 600 feet? What is the percent increase?

What is the difference from the length of the old road and the new road if the height of the hill is 600 feet? What is the percent increase?

### EZ PZ Math Tricks Determining Original Price from Final Price

Imagine you just bought an item and you wanted to know what the wholesale price was. You are told the mark up was 20%. Do you know what the initial price was if you paid $100? Watch this video for an EZ PZ way to calculate the original cost.

### TJ SIS Math Problem 2019

TJHSST admissions exam question, aka SIS, adaptation of SIS Math Problem 2019. Here is a reconstruction of the 2019 SIS Math question based on discussions with students and my own internet research.

The Chesapeake Bay holds about 18 trillion gallons of water. The Bay covers about 4,480 square miles or 2,867,200 acres. For working the problem I rounded up to three (3) million. Each acre can hold 750,000 oysters. Each oyster can filter 50 gallons of water every day. Can there be enough oysters to filter the whole Chesapeake Bay in one day?

The Chesapeake Bay holds about 18 trillion gallons of water. The Bay covers about 4,480 square miles or 2,867,200 acres. For working the problem I rounded up to three (3) million. Each acre can hold 750,000 oysters. Each oyster can filter 50 gallons of water every day. Can there be enough oysters to filter the whole Chesapeake Bay in one day?

### TJ SIS Math Problem 2018

This question is adapted from SAT # 6 section 4; questions 17-19

https://collegereadiness.collegeboard.org/pdf/sat-practice-test-6.pdf

https://collegereadiness.collegeboard.org/pdf/sat-practice-test-6.pdf

### TJ SIS Math Problem 2017

Students were given the following problem: You have a population of 1000 penguins. 500 pairs produce one chick per pair. At the end of each year there is a loss of 20% of the total population. Figure out how many penguins there will be at the end of seven years. Develop a formula that solves the problem.

### TJ SIS Math Problem 2016

This is an approximation of the February 20, 2016 TJ SIS Math Problem: It’s 5:30 AM, and as a helicopter pilot you’ve just been told there’s an injured man on a boat you need to get to a hospital. The boat is going towards where you are at 10 mph, but is currently 400 miles away. You need to get to him as soon as possible, but you only have 6600 lbs of fuel in your helicopter, which burns 1200 lbs per hour, and always travels at 150 mph. Also, you need to account for 30 min of fuel spent hovering over the boat to get the man into the helicopter, and 1 extra hour of fuel due to helicopter standards. Therefore, when can you depart your station to get the man as soon as possible?

### How to Calculate the Maximum Area of a Triangle

How to Calculate the Maximum Area of a Triangle

### Geometry Determining the Exterior Angles of a Polygon

Review of two rules to determine the exterior and interior angle of a polygon

### Exponent Rule for Multiplying and Raising to a Power

Explanation of Exponent Rule for multiplying and raising to a power

### Exponent Rule for Division

Explanation of the Exponent Rule for Division of two numbers with exponents.

### Exponent Rule for Combining Exponents with Different Bases

Explanation of Exponent Rule for Combining Exponents with Different Bases

### Changing a Quadratic Equation from Standard Form to Vertex Form

In this video you will learn how to change a quadratic equation from the standard form to the vertex form by completing the square.

### Applying Exponent Rules to Test Question CB Old SAT Book p.790 #19

Explanation of question 19 from test 7, section 7 of old SAT. P.790

### 2015 PSAT Questions 316,17 Exponent Test Question

Explanation for last 2 problems of section 3. Student Produced Response.

### 2015 PSAT Section 311 Fractional Exponents

Solving a Question Involving Fractional Exponents