Page 77 - AFCAT Solved Papers 2011 - 2019 SSBCrack eBook

51. (b) Here, Speed of man = 4.5 km/hr 55. (c) According to question,
Speed of current = 1.5 km/hr
\ Speed of man in downstream = (4.5 + 1.5) = 6km/hr (A + B)'s 1 day's work = 1
Speed of man in upstream = (4.5 – 1.5) = 3km/hr 12
´
´
2 6 3 1
\ Average speed = (B + C)'s 1 day's work =
+
(6 3) 15
´
´
2 6 3 1
= = 4 km/hr (A + C)'s 1 day's work =
9 20
52. (d) Let the number of boys and girls be 3x and 2x.
Number of those who are not scholarship holders æ 1 + 1 + 1 ö
\ (A + B) + (B + C) + (A + C) = ç 12 15 20 ø ÷
æ 80 70 ö æ 12x 7x ö 19x è
= ç 3x´ + 2x´ ÷ Þ ç + ÷ =
è 100 100 ø è 5 5 ø 5 5 4 3 ö + æ + æ 12 ö æ 1 ö
\ 2 (A + B + C) = ç 60 ÷ = ç 60 ø ÷ = ç 5 ø ÷
æ 19x ö è ø è è
\ Required percentage = ç ´ 100 ÷
´
è 5 5x ø 1
= 76% \ (A + B + C)'s 1 day's work = 10
53. (a) Ratio of times by A and B = 1 : 3
The time difference is (3 – 1) = 2 days while B takes 3 \ A, B and C together can do the work in 10 days.
days and A takes 1 day. 56. (d) Let number be x, then
If difference of time is 2 days, B takes 3 days
x + æ ç x 40 ö ´ ÷ - x = 56
æ 3 ö è 100 ø
If difference of time is 40 days, B takes ç ´ 40 ÷ = 60 days
è 2 ø
So, A takes 20 days to do the work. x + 2x - x = 56
5
1
A's 1 day's work =
20 2x = 56
5
1
B's 1 day's work =
60 56 5
´
\ x = = 140
æ 1 1 ö æ 3 1ö + 2
(A + B)'s 1 day's work = ç + ÷ = ç ÷
è 20 60 ø è 60 ø 57. (a) Total weight increase by = 15 × 1.5 = 22.5 kg
\ Weight of new man = 40 + 22.5 = 62.5 kg
4 1
= = 58. (c) Let temperature of tuesday = a, temperature of
60 15
wednesday = b and temperature of thursday = c
\ A and B together can do the work in 15 days. Sum of temperatures of tuesday to thursday = 38 × 3
5 =114
54. (b) Speed of 1st train = 90 km/hr = 90´ = 25 m/sec
18 \ a + b + c = 114
Time taken by 1st train = 36 seconds Sum of temperatures of wednesday to friday = 37 × 3
\ Distance = speed × time = 111
= 25 × 36 = 900m b + c + friday = 111
Now \ Temperature of friday = 39
2nd train is 100 meters shorter, then \ b + c + 39 = 111
\ Distance (900 – 100) = 800m \ b + c = (111– 39) = 72
5 \ a + b + c = 114
Speed of 2nd train = 45´ = 12.5 m/sec
18 a + 72 = 114
\ a = (114 – 72) = 42
800
\ Time = = 64 seconds. \ Temperature on tuesday = 42°C
12.5