Question

the average of 6 number is 30 if the average of first four is 25 and that of the last three is 35, find the fourth number

Answer 1

i have made as you can see the above image.

Answer 2

Answer:

Step-by-step explanation:

Sum of 6 numbers =60×30=180

Sum of first 4 numbers =4×25=100

Sum of last 3 numbers =3×35=105

∴ Fourth number =(100+105)−180

=205−180

=25...........