Exploring maths through problem solving

Problem of the Week

Merino Sheep Breeding

An average merino sheep in full wool now weighs about 75 kg. The weight of the average sheep has increased by about 15 kg over the past decade due to animal breeding. If this rate of increase continues, what will the average merino sheep weigh 5 years from now?


A decade is 10 years.

A 15 kg increase in one decade is a 15/10 = 1.5 kg in one year.

So the increase in 5 years is 1.5 kg x 5 = 7.5 kg.


You might notice that 5 years is half of 10 years.

So the increase in 5 years is 15 kg / 2 = 7.5 kg.


The average weight 5 years from now will therefore be 75 + 7.5 kg = 82.5 kg.

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