In a warehouse, 7 crates of goods have an average weight of 84.5 kg. One of the crates, weighing 79.2 kg, is replaced by a new crate. As a result, the average weight becomes 87.1 kg. Later, 3 more crates are added, each weighing 91.3 kg. What is the weight of the new crate that replaced the old one?
Show answer & explanation
Correct answer: C
Explanation
Given:
Number of crates = 7
Initial average = 84.5 kg
Weight of old crate = 79.2 kg
New average = 87.1 kg
Initial total weight = 7 × 84.5 = 591.5
Total weight according to new average = 7 × 87.1 = 609.7
Weight of new crate = 609.7 − (591.5 − 79.2) = 97.4
Weight of new crate = 97.4 kg