a) The quantities vary directly
b) The constant of variation is 2.5
Step-by-step explanation:
Lets us revise the direct and inverse variation
∵ 16 factory workers made 40 pieces in a certain amount of time
- If the number of worker increased, then the number of pieces
  increased in the same certain time, if the number of worker
  decreased, then the number of pieces also decrease in the
  same certain time
∴ The the number of workers and the number of pieces produce
  vary directly
∴ Number of pieces produced = k × number of worker
a) The quantities vary directly
∵ The number of worker = 16
∵ The number of pieces produced = 40
- Substitute these values in the equation of variation above
∴ 40 = k × 16
- Divide both sides by 16
∴ k = 2.5
b) The constant of variation is 2.5
Learn more:
You can learn more about variation in brainly.com/question/10708697
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