The ratio of girls to boys in a class is 3:4. If 3 new girls join and 1boy leaves, what is the new ratio of girls to boys

Answer 1

current:
number of girls -- 3x
number of boys --- 4x

after change:
number of girls -- 3x+3
numbr of boys --- 4x-1

new ratio of girls to boys
= (3x+3) : (4x-1)

more data needed to get numerical answer.
e.g. if we let x = 5
we had 15 girls and 20 boys, notice 15:20 = 3:4
after change:
we had 18 girls and 19 boys, new ratio is 18:19

if we let x = 4
we had 12 girls and 16 boys, notice 12:16 = 3 : 4
after change:
we had 15 girls and 15 boys, new ratio is 1:1

Answer 2

p varies directly as z t=400 find p when t=500