Question

5. Average of three numbers is 19 and average of first
two number is 15 then, find the third number-
Ca27
(h) 17​

Answer 1

Let the three numbers be a, b and c

According to the first condition

(a+b+c)/3=19

a+b+c=57 ..........(i)

According to the second condition

(a+b)/2=15

a+b=30

Substituting the value of a+b=30 in (i)

30+c=57

c=57-30

c=27

Therefore, the third number is 27

Answer 2

Answer:

third term is 27

Step-by-step explanation:

let three number be x,y,z

so average for  these three number is 19

(x+y+z)|3=19 then x+y+z=19*3 so, x+y+z=57 ...............eq(1)

and average for first and second  term is 15

(x+y)/2=15 then x+y=15*2 so, x+y=30 ........................eq(2)

in eq 2 we get x+y which is 30 so put in eq 1

which is x+y+z=57 and x+y=30

30+z=57

z=57-30

z=27