Chapter 2 - Kinematics: Description of Motion - Learning Path Questions and Exercises - Exercises - Page 63: 62

It is a good deal, because the other student will NOT be able to grab the dollar bill due to the reaction time.

$S=ut+\frac{1}{2}gt^{2}$ $S=0+0.5\times 9.8\times 0.2^{2}=0.196\,m=19.6\,cm$ which is greater than 15.7 cm, the dollar bill length. So, the fellow student will NOT be able to grab it.