Percentages and Word Problems Flashcards

A pulley system multiplies force by 300%. If the input force is 150 lbs, what is the output force?

Answer: 600 lbs

300% of 150 = 3.00 × 150 = 450 lbs output — wait: multiplies BY 300% means output = 300% × 150 = 450 lbs. The answer is 450 lbs.

In a batch of 80 relay switches, 7.5% are found defective. How many switches are defective?

Answer: 6

7.5% of 80 = 0.075 × 80 = 6 defective switches.

An elevator modernization project was budgeted at $85,000 but came in 12% over budget. What was the actual cost?

Answer: $95,200

$85,000 × 1.12 = $95,200.

A building's elevator log shows 840 trips on Monday and 630 trips on Tuesday. By what percentage did trips decrease?

Answer: 25%

(840 − 630) ÷ 840 × 100 = 210 ÷ 840 × 100 = 25%.

A lubricant costs $4.80 per quart. A job requires 2.5 gallons. At $4.80 per quart (4 quarts per gallon), what is the total lubricant cost?

Answer: $48.00

2.5 gallons × 4 quarts/gallon = 10 quarts; 10 × $4.80 = $48.00.

A safety test requires an elevator to carry 125% of its rated capacity. If rated capacity is 2,400 lbs, what load is used in testing?

Answer: 3,000 lbs

125% of 2,400 = 1.25 × 2,400 = 3,000 lbs.

A union contract specifies overtime at 150% of regular pay. If regular pay is $34/hr, what is the overtime rate?

Answer: $51.00/hr

150% of $34 = 1.50 × $34 = $51.00/hr.