The mean age of 5 people in a room is 28 years. A person enters the room. The mean age is now 29. What is the age of the person who entered the room?

Can someone me my sister? she is in third grade. 50 points and brainlist! ones that are not answered. plz and thx!

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.

At the "no mutants allowed" country farm, every sheep has 4 legs, every chicken has two legs, and all animals have only 1 head. asked to count how many sheep and chicken are in the fields, a farm boy reports back that there are 140 feet and 50 heads. how many sheep and chicken are there? there are sheep and chicken at the farm.