It takes 30 days to fill a laboratory dish with bacteria. If the size of bacteria colony doubles each day, how long did it take for the bacteria to fill one half of the dish?

A post office imposes a service charge of Tk. 75 per order on any money order of T 2500 or less, and Tk. 100 per order on any money order from Tk. 2501 through Tk. 7000. If a person parthases-3 money orders of Tk. 1825, Tk. 2500, and Tk. 12750, what is the total service charge for the person's money orders?

Which of the following is the smallest given that x > y > 1?

A company rents parking spaces at the rate of Tk. 100 per week or Tk. 300 per month. How much does a person save in a year (in Taka) by renting by month rather than by week?

$$\begin{gathered} p>0>q \\ \frac{Quantity A}{p + q} \frac{Quantity B}{pq} \end{gathered}$$

নীচের ধারার পরবর্তী সংখ্যা কোনটি?$১, \sqrt{৯}, ৫, \sqrt{৪৯},......;$

A mango kept in a basket doubles in every one minute. If the basket gets completely filled in 30 minutes, then in how many minutes will half of the basket be filled?