Victors Dog Fifi on a diet

If Fifi were on a diet he and he had to lose 10 kg it would take 50 weeks for him to lose the 10 kg because if every 5 weeks he loses 2 kg if you make a graph up to 25 weeks increasing by 5 he would have lost already half of the weight that he needed to then i times it by 2 and got the 50 weeks it took Fifi to lose the 10 kg.