## 10 - Messenger Going From Front To Rear Then To Front Of A Marching Army Column

**Problem**

An army of troops is marching along a road at 5 kph. A messenger on horseback was sent from the front to the rear of the column and returns immediately back. The total time taken being 10 minutes. Assuming the messenger rides at the rate of 10 kph, determine the length of the column.

## Probability That Exactly 1 is Defective in Getting 2 Cell Phones

**Problem**

A box contains 5 defective and 195 non-defective cell phones. A quality control engineer selects 2 cell phones at random without replacement. What is the probability that exactly 1 is defective?

A. 0.0190 | C. 0.0390 |

B. 0.0490 | D. 0.0290 |

## Angle Correction for Repeated Measurement

**Problem**

The following interior angles (in degree) of a triangular traverse were measured with the same precision.

Angle | Value | No. of Measurement |
---|---|---|

A |
41 | 2 |

B |
77 | 6 |

C |
63 | 2 |

What is the most probable value of angle *C*, in degrees?

A. 62.423° | C. 62.571° |

B. 62.874° | D. 62.745° |

## Expected Profit for the Acceptance of Estimate of an Engineering Company

**Problem**

An engineering company prepares an estimate for a job. The cost of preparing the estimate is Php10,000. The amount of profit over and above the Php10,000 is Php25,000 if their estimate is accepted. The probability that their estimate will be accepted 0.7 and the probability that their estimate will not be accepted is 0.3. What is the expected profit?

A. Php12,500 | C. Php14,500 |

B. Php13,500 | D. Php10,500 |

## Rate of Change of Volume of Sand in Conical Shape

**Problem**

A conveyor is dispersing sands which forms into a conical pile whose height is approximately 4/3 of its base radius. Determine how fast the volume of the conical sand is changing when the radius of the base is 3 feet, if the rate of change of the radius is 3 inches per minute.

A. 2π ft/min | C. 3π ft/min |

B. 4π ft/min | D. 5π ft/min |

## Duel of Two 50% Marksmen: Odds in favor of the man who shoots first

**Problem**

Smith and Jones, both 50% marksmen, decide to fight a duel in which they exchange alternate shots until one is hit. What are the odds in favor of the man who shoots first?

A. 1/3 | C. 2/3 |

B. 1/2 | D. 1/4 |

## Velocity of Separation: How fast is the distance between two cars changing?

**Problem**

A Toyota Land Cruiser drives east from point *A* at 30 kph. Another car, Ford Expedition, starting from *B* at the same time, drives S30°W toward *A* at 60 kph. *B* is 30 km from *A*. How fast in kph is the distance between two cars changing after 30 minutes? Hint: Use the Cosine Law.

A. 70 kph | C. 55 kph |

B. 80 kph | D. 60 kph |