[B].
[C].
[D].
Answer: Option B
Explanation:
639 is not divisible by 7
2079 is divisible by each of 3, 7, 9, 11.
A. 8km/hr
B. 12km/hr
C. 14 km/hr
D. 15 km/hr
E. None of these
Explanation:
Speed downstream = (30 x 2/5)km/hr = 12km/hr
Speed upstream = (30 x 4/15) km/hr = 8 km/hr
Speed of boat in still water = ½ (12 + 8)km/hr = 10 km/hr
[B].
[C].
[D].
Answer: Option C
Explanation:
Let the mother’s present age be x years.
| Then, the person’s present age = | 2 | x | years. | ||
| 5 |
| 2 | x + 8 | = | 1 | (x + 8) | |||
| 5 | 2 |
2(2x + 40) = 5(x + 8)
x = 40.
| 2 |
| 5 |
[B].
| 3 |
| 4 |
[C].
| 1 |
| 4 |
[D].
| 3 |
| 5 |
Answer: Option B
Explanation:
| 4500 x x = 3375 x = | 337575 | = | 3 |
| 4500100 | 4 |
[B].
[C].
[D].
Answer: Option A
Explanation:
| Distance covered by B in 9 sec. = | 100 | x 9 | m | = 20 m. | |
| 45 |
A beats B by 20 metres.
[B].
[C].
[D].
Answer: Option B
Explanation:
Let their investments be Rs. x for 14 months, Rs. y for 8 months and Rs. z for 7 months respectively.
Then, 14x : 8y : 7z = 5 : 7 : 8.
| Now, | 14x | = | 5 | 98x = 40y y = | 49 | x |
| 8y | 7 | 20 |
| And, | 14x | = | 5 | 112x = 35z z = | 112 | x = | 16 | x. |
| 7z | 8 | 35 | 5 |
| x : y : z = x : | 49 | x | : | 16 | x | = 20 : 49 : 64. |
| 20 | 5 |
[B].
[C].
[D].
Answer: Option B
Explanation:
A : B = 100 : 90.
A : C = 100 : 72.
| B : C = | B | x | A | = | 90 | x | 100 | = | 90 | . |
| A | C | 100 | 72 | 72 |
When B runs 90 m, C runs 72 m.
| When B runs 100 m, C runs | 72 | x 100 | m | = 80 m. | |
| 90 |
B can give C 20 m.