Answer : The quantity represented by the metric system prefix deci- is 0.1
Explanation :
Metric system : The Metric System measured the things in meters, grams, liters, etc and adds prefixes like kilo, milli and centi to the count orders of the magnitude.
In metric system, a metric prefix is a unit prefix that comes before the basic unit of measure to indicate the fraction of the unit.
Metric system (factor) Prefix Symbol
1000 kilo- k
100 hecto- h
10 deca- da
0.1 deci- d
0.001 centi- c
0.0001 milli- m
0.0000001 micro- μ
Hence, according to the metric system the quantity represented by the metric system prefix deci- is 0.1