Помогите решить уровнение)

Fill in the gaps with the words : to , for ,from ,till , of , with

I have never been ... Britain before . I stayed in England ... three days . I stayed ... my friend's family . They not far ... London. ... course I went there every day . And I walked ... morning ... night . Londan is very different ... Mosckow and all other Russian towns . I took a lot ... beautiful pictures . Would you like to see them .

Костя составил уравнение. Какую задачу к нему можно придумать? a*10=16*5

можно ли заставить алюминиевую кастрюлю массой 400г плавать в 200г воды?