3 minutes and 36 seconds is the length of "Shake it off" by Taylor swift.
Source: Wikipedia
Imagine a right triangle where a and b are the legs and c is the hypothenuse.
Pitagora: a²+b²=c²
Divide by c
(a/c)²+(b/c)²=1
But a/c=sin(B) and b/c=cos(B)
Thus sin² + cos² = 1
23 is the minimum because 155 does not go into evenly and you have to have enough room for everybody, and make sure not to leave anybody out. 155 divided by 7 is 22.1428571429, you have to round it up to 23 so that everybody has a seat. Hope it helps!!
Sunscreen A will likely last longer than Sunscreen B since the IQR is larger for A than B (the Boxed portion) therefore it's likely to be more reliable.