You have to do 43 times 8 which is 344 students :)
I would not normally stop to answer this question, mainly because
there is no question asked. It's just three statements.
I do have to stop here and leave a remark, however.
Math and Physics are closely enough related that I would not
have expected to see what I see here. Although the math in
this question is reasonable, the Physics is inexcusable.
A rainbow is always a part of a circle.
Rainbows are never parabolas.
You could never cut a parabola out of paper, and then
hold it up in front of you after a rainstorm, and match it
to the rainbow.
22.
Alternate angles23.
4: (

, substitute b with 10 and a with 20 and you get 4.)
24.
0.28: 0.12 + 0.60 = 0.72. Probability is always out of 1, so 1 - 0.72 should give you the probability of losing, which is 0.28.
I believe it would be 13p im not for sure though