Deee

You could take 1 pill from jar one, 2 pills from jar 2, 3 pills from jar 3 and 4 pills from jar 4. Put them all on the scale together. measure the weight and u'll get a number. divide that number by the number of pills ie. 10 and we examine the remainder. if it is 1 than the contaminated pill is from jar 1 if it is 2 than the contaminated pill is from jar 2 if it is 3 than the contaminated pill is from jar 3 if it is 4 than the contaminated pill is from jar 4