there are 50 boys in a class. their average weight is 45 kg. when one boy leaves the class, the average reduces by 100 g. find the weight of the boy who left the class.	Choose the correct option:
A) 40.9 kg B) 42.9 kg C) 49.9 kg D) 39.9 kg E) none of these
<gadget id="calculator">50 - 1</gadget>
<output>49</output>

<gadget id="calculator">49 * 100</gadget>
<output>4_900</output>

<gadget id="calculator">4_900 / 1_000</gadget>
<output>49/10 = around 4.9</output>

<gadget id="calculator">45 + (49/10)</gadget>
<output>499/10 = around 49.9</output>

<result>C</result>
there are 50 boys in a class. their average weight is 45 kg. when one boy leaves the class, the average reduces by 100 g. find the weight of the boy who left the class.
add(45, divide(multiply(subtract(50, const_1), 100), const_1000))
here one boy is excluded and final average of the group decreases . ∴ change in average is ( – ) ve = – 0.1 kg . using the formula sum of the quantities excluded = ( changein no . ofquantities × origina laverage ) + ( changeinaverage × final no . ofquantities ) ⇒ weight of the boy who left = ( 1 × 45 ) – ( – 0.1 × 49 ) = 49.9 kg answer c