8 days
6 days
To determine the number of days Aman and Bhanu require to complete \( \frac{1}{4} \) of the job collaboratively, we must first ascertain their individual work rates and subsequently aggregate them.
Step 1: Ascertain Aman's work rate.
Aman completes 50% (equivalent to \( \frac{1}{2} \)) of the job in 16 days.
His work rate is \( \frac{1/2}{16} = \frac{1}{32} \) of the job per day.
Step 2: Ascertain Bhanu's work rate.
Bhanu completes 25% (equivalent to \( \frac{1}{4} \)) of the job in 24 days.
His work rate is \( \frac{1/4}{24} = \frac{1}{96} \) of the job per day.
Step 3: Aggregate their work rates.
Combined work rate = Aman's rate + Bhanu's rate = \( \frac{1}{32} + \frac{1}{96} \).
To sum these fractions, a common denominator is required:
\[ \frac{1}{32} = \frac{3}{96} \] (as \( 32 \times 3 = 96 \)).
Consequently, \( \frac{1}{32} + \frac{1}{96} = \frac{3}{96} + \frac{1}{96} = \frac{4}{96} = \frac{1}{24} \) of the job per day.
Step 4: Determine the time to complete \( \frac{1}{4} \) of the job together.
Given their combined work rate is \( \frac{1}{24} \) of the job per day, the time to complete \( \frac{1}{4} \) of the job is calculated as:
\[\frac{\frac{1}{4}}{\frac{1}{24}} = \frac{1}{4} \times 24 = 6 \] days.
Therefore, Aman and Bhanu collaboratively can complete \( \frac{1}{4} \) of the job in 6 days.
A box contains 16 red, 12 white, and 15 yellow identical marbles. A man picks one marble at a time without replacement. How many times must he pick a marble to be 100% certain of picking at least 3 white marbles?