1, 5 1 class boy x, 52 class girl 3x, 52 class boy y, 5 1 class girl 4y, total number, etc. X+4y=3x+y, that is, 3y=2x, x/y=3/2, y is 2, x is 3,51class girl 4y/class girl 3x = (4 *.
2.a x, B Y. The decimal point of a number is shifted to the left b y one place, that is, x/ 10 =y/5, and A is twice that of B, then x+y=30, x=20, y= 10. The ratio of A/B is 2.