Jessica runs fastest because her time/second is about 10 seconds while brookes is around 12.
Take that certain number we are looking for as 'n'
38% ⇒ 0.38
0.38n = 152
Divide by 0.38
0.38n = 152
/0.38 /0.38
n = 400
So 38% of 400 is 152.
H(t) = -16t2 + 186t + 43
at the ground h = 0
hence; -16t2 + 186t + 43 = 0
solving this quadratic equation using the quadratic formula ; a = -16, b = 186, c = 43 ; x = (-b +-(b2 - 4ac)1/2)/2a
gives t = 11.8 seconds to the nearest tenth (note that the negative root has no practical significance)
