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

(a + b + c + d + e + f)/6 = 30

(a + b + c + d)/4 = 25

(d + e + f)/3 = 105

d + e + f = 105

a + b + c + d = 100

e + f = 105 - d

(a + b + c + d + e + f) = 180

100 + 105 - d = 180

d = 25

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

So , the fourth number is 25 ♥️