Question

Average height of 20 trees is 29m.If each tress has 3m more then what will be new average

Answer 1

Find the sum of the height of the 20 trees:

Average = 29m

Sum  = 29 x 20 = 580 m

Find the increase in height

1 tree = 3m

20 trees = 3 x 20 = 60 m

Find the new sum of the height of the 20 trees:

Sum = 580 + 60 = 640 m

Find the new average:

Average 640 ÷ 20 = 32 m

Answer: The new average is 32 m

Answer 2

Average height of 20 trees = { Sum of heights of 20 trees } ÷ { 20 }


29 m = { sum of heights of 20 trees} ÷ {20}

29 × 20 m = sum of heights of 20 trees

580 m = sum of heights of 20 trees



When each tree got 3 m more : -


Average height = { sum of 20 trees + ( 3 + 3 + 3 + ...unto 20 times m ) } ÷ 20


Average height = { 580 m + 3( 1 + 1 + 1 +......upto 20 times m ) } ÷ 20


Average height = { 580 m + 3(20 m)} ÷ { 20 }


Average height = { 640 m } ÷ 20

Average height = 32 m




Therefore new average is 32 m.

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