5 trains
30mins
Let the total time taken to fill the tank be x minutes.
Then, work done by B in half hour + work done by (A+B) in half hour =1.
(
40
1
×
2
x
)+(
60
1
+
40
1
)×
2
x
=1
⇒
80
x
+
48
x
=1
⇒
240
3x+5x
=1
⇒8x=240
⇒x=30 min
7/5 * 5/q = 7/10
35/5q = 7/10
q=10
B. The Secretary, Ministry of Finance is the right answer
37 SEATS….
because if passengers will occupy 3 seats, per head amount
payable will be 26.89.80.67 can not be divisible other than
3 and 26.89. so the,
Number of occupied seats will be 3
Number of unoccupied seats will be 40-3=37
94
The 3-digit number can be written as the sequence [n, 2n, 3n]
n = 1 → [1, 2, 3] → valid
n = 2 → [2, 4, 6] → valid
n = 3 → [3, 6, 9] → valid
n = 4 → [4, 8, 12] is not valid because this would lead to a 4-digit number
any value of n > 4 would also produce invalid answer
Answer: Three numbers: {123, 246, 369}
Let the number of males be given the name M.
Let the number of females be given the name F.
If 15 females are absent, then M will be twice that of
present females.
This means that M = 2 * (F – 15)
M = 2 * F – 30.
or 2 * F – M = 30.
Now if in addition to the 15 females being absent, we also
have 45 males being absent,
then this gives the equation,
(F – 15) = 5 * (M – 45)
which simplifies to
F – 15 = 5 * M – 225
5 * M – F = 210
Pulling the equations together, we get
5 * M – F = 210
-M + 2 * F = 30
Multiply the first equation by 2, and keep the second
equation as is.
10 * M – 2 * F = 420
– M + 2 * F = 30
Add the equations.
9 * M = 450
M = 50
Verify answer.
Calculate F
from – M + 2 * F = 30
-50 + 2 * F = 30
2 * F = 30 + 50
F = 40.
If 15 females are absent, then number of males will be twice
that of females.
40 – 15 = 25.
50 = 2 * 25. Confirmed.
If also 45 males were absent, then female strength would be
5 times that of males.
Female strength is 25 due to the 15 females being absent.
50 – 45 = 5.
25 = 5 * 5. Confirmed.
Let the distance between each pole be x m. Then, distance up to 12th pole = 11x m
∴ Speed = 11x22m/s
∴ Time to cover total distance up to 20th pole
= 19x×2411x
= 41.45 s
15, 16, 34, 105, 424, 2124, 12576
The series is 15, 16, 34, 105, 424, 2124, 12576
1) (15*1) + 1 = 16
2) (16*1) + 2 = 34
3) (34*3) + 3 = 105
4) (105*4) + 4 = 424
5) (424*5) + 5 = 2125
Clearly, they gave 2124 instead of 2125, so it is the wrong number in the series.
( C ) Crawl
1200 meter
125% of s = 60
=> 1.25s = 60
=> s = 60*4/5
=> s = 48
60 – s = 60 – 48 = 12