Question 1196293
Let x = the score Allan needs to obtain in his exam

Given that the exam counts as much as two quizzes, the total average of 85 is calculated as follows:

(87 + 88 + 89 + 78 + 2x)/6 = 85*6
342 + 2x = 510
2x = 510 - 342
x = 168/2
x = 84

Answer:

Allan needs to obtain a score 84 in his exam to get average of 85.