Question

In a group of 15 persons, the average weight is 63.25 kg. a new person joined the group and the average weight decreased to 62.875kg.find the weight of the new person

Answer 1

given average weight of 15 persons = 63.25

we know that average of n terms = total of n terms / no.of terms

so by substituting above info

63.25 = total weigfht of 15 persons/ 15

63.25 * 15 = total weight of 15 persons

948.75 =  total weight of 15 persons

a new person is added... so total no.of persons wil be 16..

and also the average weight will be reduced to 62.875

new average will be = 62.875 = 885.875

if the weigjht pf the 16th person is x

then the total weight of 16 persons will be 948.75 + x

substituting the above info ....

62.875 = (948.75 + x )/16

62.875*16 = 948.75 + x

1006 = 948.75 + x

1006 - 948.75 = x

57.25 = x ..

so the weight of the new person (16th person) = 57.25