$24$ workers working $6$ hours a day finish a project in $14$ days. $21$ workers working $8$ hours a day…

$24$ workers working $6$ hours a day finish a project in $14$ days. $21$ workers working $8$ hours a day will finish the same project in:
  1. $10$ days
  2. $11$ days
  3. $12$ days
  4. $13$ days

Solution

$24 \times 6 \times 14 = 21 \times 8 \times d \Rightarrow d = \dfrac{2016}{168} = 12$ days.

Asked in: IMO

Practice more DIRECT AND INVERSE PROPORTIONS questions on Aicharya