Admission changes average weight: The average of 19 students is 15 kg. After admitting one new student, the new average becomes 14.8 kg. Find the weight of the new student.

Introduction / Context:Average shift problems involving the addition of one value are solved by recomputing totals before and after the change. The difference equals the added value.

Given Data / Assumptions:

• Initial: 19 students, average 15 kg
• After addition: 20 students, average 14.8 kg

Concept / Approach:Compute initial total, compute new total, subtract to get the new student’s weight.

Step-by-Step Solution:

Verification / Alternative check:With the new student at 11 kg, the total becomes 296 over 20 students, giving 14.8 kg average as stated.

Why Other Options Are Wrong:

• 10.6, 10.8, 14.9, 12.5 kg: do not produce the new average when recalculated.

Common Pitfalls:Using 19 in the second multiplication by mistake or misplacing decimals when multiplying 14.8 by 20.

Final Answer:11 kg