SOLUTION: The average weight of a group of children is 100 pounds. Trisha, who weighs 112 pounds, then join the group. This raises the average weight of the group to 102 pounds. How many chi

Question 67574: The average weight of a group of children is 100 pounds. Trisha, who weighs 112 pounds, then join the group. This raises the average weight of the group to 102 pounds. How many children were in the original group?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
the average weight of a group of children is 100 pounds. Trisha, who weighs 112 pounds, then join the group. This raises the average weight of the group to 102 pounds. How many children were in the original group?
:
Let x = number of children in the original group
Let y = the total weight of the original children
:
Before Trisha equation:

:
Multiply equation by x and have:
y = 100x
:
After Trisha equation:
= 102
:
Substitute 100x for y and we have:
= 102
:
Multiply equation by (x+1) and have:
100x + 112 = 102(x+1)
:
100x + 112 = 102x + 102
:
112 - 102 = 102x - 100x
10 = 2x
x = 5 kids in the original group:
:
Check: = 102

RELATED QUESTIONS
The average weight of 10 children is 88 pounds. Two more children join the group: one... (answered by stanbon)

The average weight of 10 children is 88 pounds. Two more children join the group: one... (answered by ankor@dixie-net.com)

The mean weight for a group of students is 130 pounds, with a standard deviation of 8... (answered by oscargut)

The average weight for a group of 20 women is 130 pounds. If the average weight for 3/4... (answered by stanbon)

The average weight for a group of 20 women is 130 pounds. If the average weight for 3/4... (answered by Leaf W.)

The average weight for a group of 20 women is 130 pounds. If the average weight for 3/4... (answered by checkley75,stanbon)

a mini van is rated for maximum carrying capacity of 900 pounds. a.) if the luggage... (answered by robertb)

There are several elevators in the Sandy Beach Hotel. Each elevator can hold at most 12... (answered by math_tutor2020)

Suppose that you have a huge cucumber that is 99% water (by weight). The cucumber weighs... (answered by josgarithmetic)