Help with probability please

GRE Quant Problem Solving
1

Tarik has a pile of 6 green chips numbered 1 through 6 respectively and another pile of 6 blue chips numbered 1 through 6 respectively. Tarik will randomly pick 1 chip from the green pile and 1 chip from the blue pile.

What is the probability that both chips selected by Tarik will display a number less than 4

What is the probability that either of the chips selected by Tarik will display a number less than 4

2

P(chip is <4)=3/6 or 1/2

Q1: P(green chips is<4)xP(blue chip is <4) = 0.5x0.5=0.25
Q2: P(G or B <4) = P(green chips is<4) + P(blue chip is <4) - P(G and B <4) = 0.5+0.5 - 0.25 = 0.75

3

wouldn’t “either” include both the cases as well? I vaguely remember greg mentioning it.

4

2
From the Google Lord