Final answer:
Ben must bowl 180 in his third game to have an average score of at least 170, because the sum of his first two games (142 and 188) is 330, and the sum of all three games needs to be at least 510 for an average of 170. Subtracting 330 from 510 gives us 180.
Step-by-step explanation:
To calculate the score that Ben must achieve in his third game to have an average of at least 170, we must first understand what an average means in this context. The average score is the sum of all scores divided by the number of games played. If Ben wants to have an average of 170 after three games, the sum of his three games should be at least 510 because 170 times 3 equals 510.
Ben scored 142 and 188 in his first two games, which sum up to 330 when combined. Thus, to find out what he needs to score in the third game, we subtract the sum of the first two games from the desired total sum:
Total sum needed = 170 x 3 = 510
Sum of first two games = 142 + 188 = 330
Required score for third game = 510 - 330 = 180
Therefore, the answer is (D) 180. Ben must bowl 180 in his third game to have an average of at least 170.