Question

3. The average weight of 4 girls is 50kg. When a fifth girl joins the group their average weight becomes 51kg. What is the weight of the fifth girl? A. 50.8kg C..55kg B. 50.5kg D.50.2kg ​

Answer 1

option C

Explanation:

Let's denote the weight of the fifth girl as "x".

We know that the average weight of the 4 girls is 50kg, so their total weight is 4 * 50 = 200kg.

When the fifth girl joins, the total weight of all 5 girls becomes 5 * 51 = 255kg (since the new average weight is 51kg).

Therefore, the weight of the fifth girl (x) can be found by subtracting the total weight of the original 4 girls from the total weight of all 5 girls:

x = 255 - 200 = 55kg

So the weight of the fifth girl is 55kg, which is option C.