Aptitude and Reasoning Questions

Number of non - negative integral solutions =n+r-1 Cr-1 = C223 = 253 

Father's wife — Mother;  Mother's daughter — Sister;  Sister's younger brother — My younger brother. 

So, the boy is Deepak's brother. 

Letters in the word                          Letters in the alphabet

SEQ                                                      SRQ

QUEN                                                  QPON

SEQUEN                                               SRQPO

ENTIA                                                  EDCBA 

We can select atleast one item from 6 different items = 26-1  

Similarly we can select atleast one item from other set of 6 different items in 26-1 ways. 

Required number of ways = (26-1)26-1 = 26-12 = 3969

Let the ratio of initial quantity of oils be 'x' => 4x, 5x & 8x.
Let k be the quantity of third variety of oil in the final mixture.
Let the ratio of initial quantity of oils be 'y'
From given details,
4x + 5 = 5y ..... (1)
5x + 10 = 7y .....(2)
8x + k = 9y ......(3)

By solving (1) & (2), we get
x = 5 & y = 5

From (3) => k = 5

Therefore, quantity of third variety of oil was 9y = 9(5) = 45kg.

Let Ishika and her daughter present ages be p and q

 From the given data, 

p = 4/3(p - 9)

 => p = 36 years 

Hence, Ishika's present age = 36 years and

Her daughter's present age = 1/6 x 36 = 6 years 

Now, required her daughter’s age three years ago = 6 - 3 = 3 years.

Let the speed of the faster train be 'S' kmph

Then speed of the slower train will be '(S-5)' kmph

Time taken by faster train = 350/S hrs

Time taken by slower train = 350/(S-5) hrs

 350s-5 - 350s = 2 hrs 20 min = 213 = 73

=> S = 30 km/hr.

A Perch is a fresh water fish. Similarly, a cod is a salt water fish.

Hence, Perch : Fresh Water :: Cod : Salt water.