8/12/2019 Present Econ

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ANDRO S. REBUYAS BSCE – 4A

1.) A diesel engine uses Type A filter and high-grade lubricant oil consisting $5.50 per liter. With this filter, the oil and the filter have

to be changed every 500 hours of operation, and 5 liters of oil have to be added every 100 hours. This filter costs $148 a piece.

Eighty liters of oil fill the engine. Another type, filter B, costing $120 may be used with a lower grade of oil costing $4.80 per liter.

However, if this filter is used, the oil and filter have to be changed every 300 hours, and 10 liters are added after each 150 hours the

engine is used. Which type of filter and oil would you recommend?

2.) A construction company in Manila will bid on the digging of an irrigation canal in a nearby province which measures 2 meters

wide, 1 meter deep, and 2 km long. Twenty labourers will be employed at P120 each per day, and they can dig, on the average of ½

cubic meters per hour. In addition, 2 foreman will also be employed at P250 each per day. A dicth-digging machine may be rented at

a cost of P750 a day, in actual use and in transit to and from the construction site. In actual use, fuel and oil will cost P280 a day.

Freight charges for transporting the machine will be P1200 each way. The machine operator accompanies the machine and is paid

P280 each day. The services of 2 laborers would also be needed, in addition to the services of the machine. The machine can dig 1

cubic meter every 4 minutes.

Allowing P20,000 for profit and contingencies, determine the lowest bid price of the company.

3.) A company manufactures 1,000,000 units of a product yearly. A new design of the product will reduce materials cost by 12%, but

will increase processing cost by 2%. If materials cost is $1.20 per unit and processing will cost $0.40 per unit, how much can the

company afford to pay for the preparation of the new design and making changes in equipment?

4.) A certain masonry dam requires 200,000 cubic meters of gravel for its construction. The contractor found two possible sources

for the gravel with the following data.

SOURCE A SOURCE B

AVERAGE DISTANCE, GRAVEL PIT TO

DAM SITE

3.0 KM 1.2 KM

GRAVEL COST/CU.M AT PIT $10.00

PURCHASE PRICE OF PIT $800.00

ROAD CONSTRUCTION NECESSARY $450.00

OVERBURDEN TO BE REMOVED AT $4.20

PER CUBIC METER

90,000 CU. M

HAULING COST PER CU.M PER KM $4.00 $4.00

Which of the two sites will give lesser cost?

5.) Two workers, A and B, produce the same product on identical machines. A receives $25 per hour and he produces 100 units per

hour. B is able to produce 120 units per hour. The machine rate or cost of operation of the machines used by them is $100 per hour.

  Determine the cost per piece for worker A.

  Determine the hourly wage of worker B in order that his cost per piece will equal that of A.

A set of tools costs P1,800 and can be ground twenty times. Each regrinding costs P18 and the time needed to regrind and change

tools is 1 hour. The machine operator is paid P28 per hour including the time the tool is changed. The tool grinder who also sets the

tools to the machine is paid P25 per hour. The hourly rate chargeable against the machine is P54, regardless of machine speed.

Which speed is the most economical?

6.) A machine used for cutting materials in a factory has the following outputs per hour at various speeds and requires periodic tool

regrinding at the intervals cited.

SPEED OUTPUT PER HOUR TOOL REGRINDING

A 200 PIECES EVERY 8 HRS

B 250 PIECES EVERY 7 HRS

C 280 PIECES EVERY 5 HRS7.) A contractor has a job which should be completed in 100 days. At present, he has 80 men on the job and it is estimated that they

will finish the work in 130 days. Of the 80 men, 50 are each paid $120 a day, 25 at $180, and 5 at $250 a day. For each day beyond

the original 100 days, the contractor has to pay $500 liquidated damages.

  How many more men should the contractor add so that he can complete the work on time?

  If of the additional men, 2 are paid $180 a day, and the rest at $120 a day, would the contractor save money by employing

more men and not paying the fine?