Dibyendu D. answered • 12/08/19

More than 2 years of experience in teaching SAT/ACT/GRE/GMAT Math

If each boy is eligible for all the prizes, the 1^{st} prize can be given away to any one of the boys and thus it can be given away in **3 different ways**.

Similarly, the 2^{nd} prize can be given away to any one of them in **3 different ways** again and so on.

Hence, the total number of way all 4 prizes can be given away is **3*3*3*3 = 3**^{4}** = 81**