There are five students in a class, S1, S2, S3, S4 and S5 Average score of the class in the unit

Q. There are five students in a class, S1, S2, S3, S4 and S5. Average score of the class in the unit test is ______ , while average score of S1 and S3 together is _______more than average score of S2 and S4 together. Score of S3 is 50% more than S5, while the score of S2 is 12 less than S5. Score of S4 is __________more than S5. Marks obtained by S5_______                                  

Find which of the following blanks will satisfy the blanks in the same order.

I. 36, 9, 18, 30

II. 18.6, 3, 8, 20

III. 58, 5, 2, 60

A.I only

B.III only

C.II only

D.I and III only

E. None of these

Ans: I and III only

Sol:

I. 180, 9, 18, 30
S5 = 30
S4 = 30 + 18 = 48
S3 = 150% x 30 = 45
S2 = 30 – 12 = 18
Also,
(S1 + S3)/2 = 9 + (S2 + S4)/2
S1 = 18 + 18 + 48 – 45
S1 = 39
Required average = (39 + 18 + 45 + 48 + 30)/5 =
36
This option is true.
II. 18.6, 3, 8, 20
S5 = 20
S4 = 20 + 8 = 28
S3 = 150% x 20 = 30
S2 = 20 – 12 = 8
Also,
(S1 + S3)/2 = 3 + (S2 + S4)/2
S1 = 6 + 8 + 28 – 30
S1 = 12
Required average = (12 + 8 + 30 + 28 + 20)/5 =
18.6
This option is not true.
III. 58, 5, 2, 60
S5 = 60
S4 = 60 + 2 = 62
S3 = 150% x 60 = 90
S2 = 60 – 12 = 48

Also,
(S1 + S3)/2 = 5 + (S2 + S4)/2
S1 = 10 + 48 + 62 – 90
S1 = 30
Required average = (30 + 48 + 90 + 62 + 60)/5 =
58
This option is true.
Hence answer is option D