Dear Reader, while one can expect a lot of questions to answer in short time in Tech Mahindra papers. These might not be difficult to answer, but by practicing well and knowing important formulas, you can be really fast while solving. Below are four sample questions for your practice.
A cylinder of diameter 14 and height 7 is converted into a cone of radius 6. Now, what could be the percentage height of the new shape ?
a. 308% b. 32% c. 2150% d. 215%
Answer: a. 308%
Volume of cylinder = pi X r2 X h = pi X 49 X 7 = 343pi
Volume of the cone = Volume of cylinder = 343pi -> eq 1
Volume of cone is given by formula = 1/3 (pi X r2 X h) = 36/3(pi)(h) = 12(pi)(h)--> eq 2 (here h is the height of the cone)
From eq 1 and eq 2 we get 343pi = 12(pi)(h)
Therefore, height of the cone = 343/12
Percentage increase in height = ((height of the cone - height of the cylinder )/ height of the cylinder) X 100%
= (343/12 - 7)/7 X 100
= 259/84 X 100
= 308% approximately.
Find the largest number which gives out reminders 2 and 5 when used to divide 80 and 122.
a. 19 b. 17 c. 13 d. infinite number of solutions
Answer: c. 13.
This is a very simple question where finding out the HCF of 80 - 2 and 122 - 5 will give the answer.
The HCF of 78 and 117 is 13
Hint : In case you are confused about HCF, LCM stuff, you can very well do a trial and error with options which is not a difficult task but could consume a little more time than the direct method.
Find the ratio of the volumes of a sphere and cone of same radius. Also the height of the cone is twice its radius.
a. 3 : 1 b. 4 : 3 c. 4 : 1 d. 2 : 1
Answer : d. 2 : 1
This is again a simple question that can be answered by knowing formulas.
Volume of a cone = 1/3 pi r2 h where r is the radius and h is the height of the cone.
Now, h = 2r as per the question.
Hence volume of the cone = 2/3 pi r3
Volume of a sphere = (4/3) pi r3 where r is the radius which is the same as that of the cone.
Ratio of volume of sphere to that of cone = (4/3) pi r3 / 2/3 pi r3 = 2 : 1
Find the missing number in the sequence 504 , _ , 990, 1320, 1716
a. 720 b. 1000 c. 721 d. 790
Answer : a. 720
The given sequence is of the form n3-n where n starts from 8. Hence the blank should be filled by 93-9 which is 720.