Some of the scientific questions that may be answered through the experiment are:
(1) What are the physical changes that may occur in the solution or the indicator when added with acidic/basic solution?
(2) How much of the indicator is needed in order to bring about a significant physical change in the solution to identify its H+ concentration?
Answer:
108 extended days
Explanation:
Regular school hours a day = 6 hr
No. of school days to make up by extending the regular hours = 3 days
Amount of time added to the regular hours of school = 10 min
No. of extended school days to make up the 3 school days by following the above mentioned criteria be x.
Time of school hours in 3 days = 
are required to make up 3 days of school having 6 hours of regular timing with 10 minutes of add-on time each day.
Let distance be x.
Time in going, t 1 = x/50
Time in coming, t 2 = x/40
Total time T = x/40 +x/50 = 9x/200
Average speed = total distance/ total time
=( x+x)/(9x/200)= 2x ×200/9x = 400/9 = 44.44 km/h
Time = distance / speed
Time = (4,800 meters) / (3 x 10⁸ m/s)
<em>Time = 0.000016 second</em>
This number is not one of the choices on the list. My hunch is that you copied the distance wrong.
If the estimated distance to the star is actually 4.8 x 10¹⁵ km, instead of 4.8 km, then the answer would be close to 500 years <em>(B)</em>.
There's no way a star can be "4.8 km away from the Earth". You can <em>walk</em> that far in about an hour, and passenger jet airplanes fly <em>twice</em> as far as that away from the Earth !
