To solve this, you can create an equation. Say the weight of Umbar is x, then Saira weighs x+25. Together they weigh 205. So, you get the equation
x+x+25=205
Then solve for x.
2x+25=205
2x=180
x=90
Then to find Saira's weight, add 25 to Umbar's weight.
90+25=115.
