Question

The average age of 4 sisters is 20. If the ages of
3 sisters are 16 yr, 18 yr and 20 yr, the age of
the fourth sister is​

Answer 1

$\huge \underline \mathcal \purple{Answer}$

$The \: average \: is \: 20 \\ </p><p>Let \: the \: age \: of \: fourth \: sister \: be \: x. \: \\ </p><p>Now, \\ </p><p> = > (16+18+20+x)/4=20 \\ </p><p> = > 54+x/4=20 \\ </p><p> = > 54+x=20*4 \\ </p><p> = > 54+x=80 \\ </p><p> = > x=80-54 \\ </p><p>=26 years$

Answer 2

Answer:

the age of the fourth sister is 26 yrs