To convert percentages to fractions, just divide by 100. So 60% for example is 0.60 or 3/5.
The apples weigh 60% of 200kg=120kg.
80kg are other fruit. 60% of 80kg=48kg of pears, leaving 32kg of peaches.
Percentage of peaches=32/200*100=16%.
Another way of solving this doesn’t involve the original weight of 200kg:
If 60% of the fruit is apples then 40% is other fruit and 60% of 40% is 24%. So 24% is pears. 40% of 40% is 16% which is peaches.