Question

7. The average of first three numbers from
four numbers is 18 and the last three is
16. If last number is 19, then first
number is​

Answer 1

Answer:

according to question.....

let the numbers be  a b c d

then

(a+b+c)/3 = 18

(a+b+c) = 54......................eq1

(b+c+d)/3 = 16

(b+c+d) = 48......................eq2

from equation 1 & 2

54-a = 48-d

a - d = 54-48

a- d = 6

and we know that d = 19

then

a = 6+19

a = 25

i hope you got the solution