Cool ok so chat me and I'll help
Plug in 31 where h is assuming that's what the variable h represents.
31 - 15 = 3.2t
16 = 3.2t
Divide both sides by 3.2
t = 5
Five thousand six hundred seventy eighty and three hundred twenty one
1/2 because if there's at least 1 boy that same boy could be the elder child so 1 could be a boy and the other a girl younger than him