Quantitative Aptitude - Arithmetic Ability Questions

I
= ptr

Therefore, the total amount the owner received on January 17, 2001 was

$1295.57 + $10.47 =
$1306.04

Let the speed of boat in still water is ‘x’ km/hr & that of stream is ‘y’ km/hr.
Then, ATQ
(x+y)/y = 9/1 9y = x + y
x = 8y
y = 3 km/hr
So, x = 24 km/hr
Upstream speed = 24-3 = 21 km/hr
Hence, distance travelled upstream in 5 hours = 21*5 = 105 km.

Let the present age of Deepa = 5p

Let the present age of Hyma = 6p

After four years their ratio = 6 : 7

=> 5p + 46p + 4 = 67

=> 35p + 28 = 36p + 24

=> p = 4

Therefore, the difference between their ages = 24 - 20 = 4 years.

$$\begin{gathered} 75x321415 ÷ 525100 \\ 94 ÷ 525100 \\ 9002100 \\ = 37 \end{gathered}$$

He can arrange his schedule in 8P6 = 20160 ways

Two horses A and B, in a race of 6 horses... A has to finish before B

if A finishes 1... B could be in any of other 5 positions in 5 ways and other horses finish in 4! Ways, so total ways 5*4!

if A finishes 2... B could be in any of the last 4 positions in 4 ways. But the other positions could be filled in 4! ways, so the total ways 4*4!

if A finishes 3rd... B could be in any of last 3 positions in 3 ways, but the other positions could be filled in 4! ways, so total ways 3*4!

if A finishes 4th... B could be in any of last 2 positions in 2 ways, but the other positions could be filled in 4! ways, so total ways... 2 * 4! 

if A finishes 5th .. B has to be 6th and the top 4 positions could be filled in 4! ways..

A cannot finish 6th, since he has to be ahead of B

Therefore total number of ways = 5*4! + 4*4! + 3*4! + 2*4! + 4! = 120 + 96 + 72 + 48 + 24 = 360

The given 3b - 7 < 32 can be solved as

3b - 7 < 32

3b < 39

b < 13.

P1+20100n > 2P 

Now, (6/5 x 6/5 x 6/5 x 6/5) > 2.

So, n = 4 years.