Quantitative Aptitude - Arithmetic Ability Questions

As per the BODMAS rule, Addition and subtraction can be treated on same priority (from left to right) when they are in consecutive order.

65% × 700 + 14 - 9 × 3 65 × (700/100) + 14 - 27 455 + 14 - 27 = 442

Speed =   6005×60 m/sec= 2 m/sec = 2 x (18/5) km/hr = 7.2 km/hr

Let the numbers 13a and 13b.

Then, 13a x 13b = 2028

=>ab = 12.

Now, the co-primes with product 12 are (1, 12) and (3, 4).

[Note: Two integers a and b are said to be coprime or relatively prime if they have no common positive factor other than 1 or, equivalently, if their greatest common divisor is 1 ]

So, the required numbers are (13 x 1, 13 x 12) and (13 x 3, 13 x 4).

Clearly, there are 2 such pairs.

Let the two conditioners be A and B

'A' cools at 40min

'B' at 45min

Together = (a x b)/(a + b)

= (45 x 40)/(45 + 40)

= 45 x 40/85

= 21.1764

= 22 min (approx).

Suppose B joined for x months . Then,  ( 85000 * 12 )/(42500 * x) = 3. or x = (85000 * 12) / (42500 * 3) = 8.

So, B joined for 8 months.

Here the series follows,

194

194 - (1x1 - 1) = 194

194 - (2x2 - 1) = 191

191 - (3x3 - 1) = 183

183 - (4x4 - 1) = 168

168 - (5x5 - 1) = 144

Man's rate in still water = (15 - 2.5) km/hr = 12.5 km/hr.

Therefore,  Man's rate against the current = (12.5 - 2.5) = 10 km/hr.