The adult passed statements of the problem on skis 900m in 3 min. and the boy of 400 m in 2 min. on how many passed more meters in 1 min. the adult than the boy. I will give 57 points for a statement of the problem urgently.

Condition on a photo below. If you do not use alphabetic references for a condition, then instead of letters S, t, write V--distance, time and speed. Resheniye: 1) 900:3=300 (m/min) adult's speed. 2) 400:2=200 (m/min) speed of the child 3) 300-200=100 (m/min).
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