Question

when 6 new boys were admitted and 6 girls left the class the percentage of girls decreased from 68 to 56. find the original nunber of girls and boys in the class.

full solution only​

Answer 1

Answer:

let g = original number of girls

let b = original number of boys

then

(g+b) = total in the class

:

First equation

g%2F%28g%2Bb%29 = .68

g = .68(g+b)

g = .68g + .68b

g - .68g = .68b

.32g = .68b

g = %28.68b%29%2F.32

g = 2.125b

:

Second equation

Adding 6 boys and subtracting 6 girls, class total is the same

%28g-6%29%2F%28g%2Bb%29 = .56

g - 6 = .56(g+b)

g - 6 = .56g + .56b

g - .56g = .56b + 6

.44g = .56b + 6

Replace g with 2.125b

.44(2.125b) = .56b + 6

.935b - .56b = 6

.375b = 6

b = 6/.375

b = 16 boys originally

:

Find the girls

g = 2.125(16)

g = 34 girls originally

:

;

See if this checks out, total is 16 + 34 = 50

34/50 = .68

and 6 less girls

28/50 = .56

Answer 2

Answer:

Step-by-step explanation: