in the first half he would have swam 1 km. there are 1000m in a km so 1000/200=5 so he swam the first 200 fly, then a 200 breast, then a 200 fly again, then another 200 breast the finish the first 1 km with a 200 fly. so we switched strokes 4 times.
PS i wouldn't recommend doing a 2 km swim fly and breast
21,985,233 to the millions place is 22,000,000
Answer=3/10
Step wise =
Total number of student=40
student who eat Hamburger=12
now,
Probability of eating hamburger student = 12/40
=3/10
2. f(x) = x - 2x² - 5 + 10x
=-2x² + 8x - 5
f'(x)= -4x + 8
4. y = 100(45x - 30 - 3x³ + 2x²)
= 100(-3x³ + 2x² + 45x -30)
= -300x³ + 200x² + 4500x - 3000
y' = -900x² + 400x + 4500
