## 08 - Sound of Impact be Heard Before the Report of the Gun

**Problem**

A bullet is fired at a target 1,342 m away. At what point along its path would the sound of the impact of the bullet be heard 1/4 second before the report of the gun, assuming that sound travels at the rate of 335 m/sec and the bullet is 503 m/sec.

## 05 - Sum and Difference of Two Numbers Multiplied to Sum and Difference of Their Squares

**Problem**

Find two numbers such that their sum multiplied by the sum of their squares is 5500, and their difference multiplied by the difference of their squares is 352.

## 07 - A Man Covers an Unknown Distance at Different Rates

**Problem**

A man covers the distance *A* to *B* in 5 hours and 30 minutes. During the second half of the distance he traveled 1/2 kilometer less per hour than during the first half. In the return trip from *B* to *A*, by traveling 1 km/hr faster than during the first half of his trip from *A* to *B*, he consumed 3-3/4 hours. Determine the distance *AB*.

## Numbers 4, 2, 5, and 18 are Added Respectively to the First Four Terms of AP, Forming Into a GP

**Problem**

If 4, 2, 5, and 18 are added respectively to the first four terms of an arithmetic progression, the resulting series is a geometric progression. What is the common difference of the arithmetic progression?

## 06 - The Battleship Was Brought to Full Stop After 1 Hour of Voyage

**Problem**

A battleship started on a 500-mile voyage but was brought to full stop an hour after starting for military reasons, delaying it for full hour, after which it was ordered to proceed at a reduced velocity equivalent to 75% of its former rate. The ship arrived at its destination 3 hours and 3 quarters after scheduled time. If it was desired for the ship to arrive one hour and a quarter sooner, how far from the destination should the ship have been ordered stopped?

## 04 - In a Mixed Company of ASEAN Nationalities

**Problem**

In a mixed company of Malaysians, Vietnamese, Singaporeans, Thais, and Filipinos, the Malaysians are one less than 1/3 of the Filipinos; and three less than half the Vietnamese. The Filipinos and Thais outnumber the Singaporeans and Vietnamese by 3. The Singaporeans and Filipinos form one less than half the company, and the Singaporeans and Vietnamese form 7/16 of the company. How many persons of each nationality were there?

## Angle Between Two Zero-Based Vectors in XY-Plane

**Problem**

What is the angle between zero-based vectors ${\bf V_1} = (-\sqrt{3}, ~ 1)$ and ${\bf V_2} = (2\sqrt{3}, ~ 2)$ in an *x*-*y* coordinate system?

A. 0° | C. 150° |

B. 180° | D. 120° |