A clerk encoded 120, 135, 150 and 115 records on four days. How many must she encode on the fifth day to average 130 a day?
Correct answer: C. 130
To average 130 over 5 days she needs 5 × 130 = 650 records. She has 120 + 135 + 150 + 115 = 520, so she needs 650 − 520 = 130 more.
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