Question

4. A
The average of 8 numbers is 20,
that of the first two is 15.5 and that
of the next three is 21-, the 6th is
1
3
less than the 7th by 4 and 7 less
than the eighth. The last number is
(AF 25 (B) 28 (C) 32 (D) 35
1. D 2. A 3. B 4. C​

Answer 1

Answer:

25

Step-by-step explanation:

Sum of 8 numbers =20×8=160

Sum of first 5 numbers =15.5×2+364×3

=31+64

=95

Sum of last 3 numbers =(160=95)=65

Let 6th,7th and 8th number be x,y,z respectively

y−x=4.....(1)

z−x=7.....(2)

z−y=3.....(3)

x+y+z=65.....(4) [From (1)$ and (2)]

From (3) and (4)

z−x=7

⇒z=25.