Cognizant Aptitude Questions

1. Three cubes of edges 6 cms, 8 cms and 10 cms are meted without loss of metal into a single cube. The edge of the new cube will be:
   1. 8 cms
   2. 12 cms
   3. 14 cms
   4. 16 cms
   Answer & Explanation
   Answer: Option B
   Volume of new cube = Volume of cube 1 + cube 2 + cube 3 = 6³ + 8³ + 10³, = 216 + 512 + 1000
   a³ = 1728,
   a = (1728)^1/3 = 12

2. If 378 coins consist of rupee, 50 paise and 25 paise coins, whose values are proportional to 13 :11 : 7, the number of 50 paise coins will be :
   1. 128
   2. 132
   3. 133
   4. 136
   Answer & Explanation
   Answer: Option B
   If values are proportional to 13 : 11 : 7, then the number of coins will be proportional to 13/1 : 11/0.50 : 7/0.25 ⇒ 13 : 22 : 28. Now from this the number of coins of 50 paise will be 378 × 22/63 = 132.
3. A person travels 48 kms at 12 kms/hour and further 48 kms at 16km.s/hour. His average speed for the whole
   1. 14 km/hour
   2. 13(4/7)km/hour
   3. 12(5/7)km/hour
   4. 13(5/7)km/hour
   Answer & Explanation
   Answer: Option D
   Avg. Speed = (Total Distance / Total Time)
   TD = 48 + 48= 96,
   T₁ = 48/12 = 4hrs
   T₂ = 48/16 = 3hrs
   T₁ + T₂ = 4 + 3 = 7
   Avg Speed = 96/7 = 13(5/7) km/hr

4. Simplify (0.001344 / 0.3 x 0.7) = ?
   1. 0.0064
   2. 0.064
   3. 0.64
   4. 6.4
   Answer & Explanation
   Answer: Option A
   (0.001344 / 0.3 x 0.7) = 0.0064
5. The difference of two numbers is 11 and one fifth of their sum is 9. The numbers are :
   1. 31, 20
   2. 30, 19
   3. 29, 18
   4. 28, 17
   Answer & Explanation
   Answer: Option D
   x − y = 11, x + y = 5 × 9 x − y = 11, x + y = 45, y = 17, x = 28

6. How many numbers between 1 and 100 are divisible by 7 ?
   1. 9
   2. 11
   3. 17
   4. 14
   Answer & Explanation
   Answer: Option D
   No. of divisible by 7 7, 14 --------- 98, n = a + (N - 1)d
   98 = 7 + (N - 1) 7, 98 = 7 + 7N - 7
   98/7= N = 14
7. What is the number which when multiplied by 13 is increased by 180?
   1. 13
   2. 15
   3. 23
   4. 35
   Answer & Explanation
   Answer: Option B
   13 × 15 = 195
8. In 24 minutes, the hour hand of a clock moves through an angle of:
   1. 60°
   2. 24°
   3. 12°
   4. 5°
   Answer & Explanation
   Answer: Option C
   12 hour = 360°, 1 hr. = 360/12 = 30° 60 min = 30°, 1 min 30/60 = .5° 24 min. = 1/2 ×24 = 12°
9. √0.0081 is equal to :
   1. 0.09
   2. 0.9
   3. ±0.08
   4. 0.81
   Answer & Explanation
   Answer: Option A
   √0.0081 = √0.0081/10000 = √81/10000 = 9/100 =0.09
10. A reduction of 20% in the price of mangoes enables a person to purchase 12 more for Rs. 15. What was the price of 16 mangoes before reduction of price ?
    1. Rs. 6
    2. Rs. 5
    3. Rs.7
    4. Rs. 9
    Answer & Explanation
    Answer: Option B
    Price x Consumption = Expenditure
    Consumption = Exp. Price
    (15 / 8x) - (15 / x) = 12
    x = (15 x 2) / (12 x 8)
    For 16 Mangoes = [(15 x 2) / (12 x 8)] x 16 = 5