Answer: (a) 6
(b) 14
Step-by-step explanation:
Let a represent the unknown digit for Chinese --> 70 + a
Let b represent the unknown digit for Mathematics --> 80 + b
Total scores ÷ Total number of tests = Average
[tex]\dfrac{78 + (70 + a) + (80 + b) + 62}{4}=76\\\\\\\dfrac{290 + a + b}{4}=76\\\\\\290 + a + b=304\\\\\\a+b=14[/tex]
The two digits must add up to 14.
The only options are: (9,5), (8,6), (7,7), (6,8), and (5,9),
Mathematics - Chinese
(9, 5) 89 - 75 = 14 LARGEST Difference
(8, 6) 88 - 76 = 12
(7, 7) 87 - 77 = 10
(6, 8) 86 - 78 = 8
(5, 9) 85 - 79 = 6 SMALLEST Difference
