Question

Difficulty: MediumRatios, Rates, and Proportions

A high-speed digital camera records 480480 frames every 33 seconds. The camera operator increases the recording rate by 25%25\%. At this new recording rate, how many total frames will the camera record in 1414 seconds?

  1. A
    1,6801,680
  2. B
    2,2402,240
  3. 2,8002,800Answer
  4. D
    3,9203,920
  5. E
    8,4008,400

Answer

The camera will record 2,800 frames in 14 seconds at the new recording rate.
To solve this problem, first determine the initial frame rate: 480480 frames divided by 33 seconds equals 160160 frames per second. Increasing this rate by 25%25\% produces 160×1.25=200160 \times 1.25 = 200 frames per second. Multiplying the new rate by 1414 seconds results in 200×14=2,800200 \times 14 = 2,800 frames.

Step-by-Step Solution

1
Calculate the original unit rate in frames per second.
480 frames3 seconds=160 frames per second\frac{480 \text{ frames}}{3 \text{ seconds}} = 160 \text{ frames per second}
Dividing the number of frames by the elapsed time yields the frame rate per second.
2
Determine the new unit rate after a 25%25\% increase.
160×(1+0.25)=160×1.25=200 frames per second160 \times (1 + 0.25) = 160 \times 1.25 = 200 \text{ frames per second}
Increasing a value by 25%25\% is equivalent to multiplying the original value by 1.251.25.
3
Calculate total frames recorded in 1414 seconds at the new rate.
200 frames per second×14 seconds=2,800 frames200 \text{ frames per second} \times 14 \text{ seconds} = 2,800 \text{ frames}
Multiplying the new rate by the given duration yields the total frame count.

Key Concept

Unit rates and percentage adjustment in rates
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