MATH 51

A man left his home at past 3:00 o’clock PM as indicated in his wall clock, between 2 to 3 hours after, he returns home and noticed the hands of the clock interchanged. At what time did the man leave his home?

• a. 3:31.47

• b. 3:21.45

• c. 3:46.10

• d. 3:36.50

From the time 6:15 PM to the time 7:45 PM of the same day, the minute hand of a standard clock describe an arc of

• a. 60°

• b. 90

• c. 180°

• d. 540°

A storage battery discharge at a rate which is proportional to the charge. If the charge is reduced by 50% of its original value at the end of 2 days, how long will it take to reduce the charge to 25% of its original charge?

• 3

• 4

• 5

• 6

The resistance of a wire varies directly with its length and inversely with its area. If a certain piece of wire 10 m long and 0.10 cm in diameter has a resistance of 100 ohms, what will its resistance be if it is uniformly stretched so that its length becomes 12 m?

• a. 80

• b. 90

• c. 144

• d. 120

Given that “w” varies directly as the product of “x” and “y” and inversely as the square of “z” and that w = 4 when x = 2, y = 6 and z = 3. Find the value of “w” when x = 1, y = 4, and z = 2.

• 3

• 4

• 5

• 6

If x varies directly as y and inversely as z, and x = 14 when y = 7 and z = 2, find the value of x when y = 16 and z = 4.

• 14

• 4

• 16

• 6

The electric power which a transmission line can transmit is proportional to the product of its design voltage and current capacity, and inversely to the transmission distance. A 115-kilovolt line rate at 100 amperes can transmit 150 megawatts over 150 km. how much power, in megawatts can a 230 kilovolt line rate at 150 amperes transmit over 100 km?

• a. 785

• b. 485

• c. 675

• d. 595

The time required for an elevator to lift a weight varies directly with the weight and the distance through which it is to be lifted and inversely as the power of the motor. If it takes 30 seconds for a 10 hp motor to lift 100 lbs. through 50 feet, what size of motor is required to lift 800 lbs. in 40 seconds through 40 feet?

• 42

• 44

• 46

• 48

The selling price of TV set is double that of its cost. If the TV set was sold to a customer at a profit of 25% of the net cost, how much discount was given to the customer?

• a. 33.7%

• b. 35.7%

• c. 37.5%

• d. 34.7%

A group of EE examinees decided to hire a mathematics tutor from Excel Review Center and planned to contribute equal amount for the tutor’s fee. If there were 10 more examinees, each would have paid P 2 less. However, if there were 5 less examinees, each would have paid P 2 more. How many examinees are there in the group?

• 14

• 16

• 18

• 20