1.A school assembly has 179 students in it. Nine teachers escort "k" number of
students out of the assembly, until there are 26 students remaining.
2. a i guess
x = r sin θ cos Ф
x² = r² sin² θ cos² Ф
y = r sin θ sin Ф
y² = r² sin² θ sin² Ф
z = r cos θ
z² = r² cos² θ
x² + y² + z²
= r² sin² θ cos² Ф + r² sin² θ sin² Ф + r² cos² θ
= r² sin² θ (cos² Ф + sin² Ф) + r² cos² θ
= r² sin² θ + r² cos² θ
= r² (sin² θ + cos² θ)
= r² √
3x : 2 = 15
3x = 15 * 2
3x = 30
x = 30 : 3
x = 10
--------------------------------
3(10) :2 = 15
