[B].
[C].
[D].
Answer: Option C
Explanation:
Go on multiplying 2 and adding 1 to get the next number.
So, 39 is wrong.
[B].
[C].
[D].
Answer: Option C
Explanation:
Let the speed of the slower train be x m/sec.
Then, speed of the faster train = 2x m/sec.
Relative speed = (x + 2x) m/sec = 3x m/sec.
| (100 + 100) | = 3x | |
| 8 |
24x = 200
| x = | 25 | . |
| 3 |
| So, speed of the faster train = | 50 | m/sec |
| 3 |
| = | 50 | x | 18 | km/hr | |
| 3 | 5 |
= 60 km/hr.
[B].
[C].
[D].
Answer: Option D
Explanation:
This is an A.P. in which a = 51, l = 100 and n = 50.
| Sum = | n | (a + l) | = | 50 | x (51 + 100) = (25 x 151) = 3775. |
| 2 | 2 |
[B].
[C].
[D].
Answer: Option E
Explanation:
Numbers must be (14)2, (13)2, (12)2, (11)2, (10)2, (9)2, (8)2.
So, 80 is wrong.
A. 625
B. 630
C. 640
D. 650
Explanation:
Let the sum be Rs. x. Then,
[x (1 + 4/100)2 – x] = (676/625 x – x) = 51/625 x
S.I. = (x * 4 * 2)/100 = 2x/25
51x/625 – 2x/25 = 1 or x = 625.
[B].
[C].
[D].
Answer: Option C
Explanation:
‘LOGARITHMS’ contains 10 different letters.
| Required number of words | = Number of arrangements of 10 letters, taking 4 at a time. |
| = 10P4 | |
| = (10 x 9 x 8 x 7) | |
| = 5040. |
[B].
[C].
[D].
Answer: Option D
Explanation:
| Quantity of milk = | 60 x | 2 | litres = 40 litres. | |
| 3 |
Quantity of water in it = (60- 40) litres = 20 litres.
New ratio = 1 : 2
Let quantity of water to be added further be x litres.
| Then, milk : water = | 40 | . | ||
| 20 + x |
| Now, | 40 | = | 1 | ||
| 20 + x | 2 |
20 + x = 80
x = 60.
Quantity of water to be added = 60 litres.