Tuesday, 19 August 2014

TCS - Recent Questions - 2

TCS – Recent Questions - 2

1.        A student's average (arithmetic mean) test score on 4 tests is 78. What must be the students score on a 5th test for the student’s average score on the 5th test to be 80?
Ans: 88
Average of four tests -> 78.  Total of 4 tests -> 78 x 4 -> 312.
Average of five tests ->  80.  Total of 5 tests->  80 x 5 -> 400
Hence, the student should score 400 – 312 = 88 marks in the fifth test.

2.            Rural households have more purchasing power than the urban households at the same income level, since some of the income urban and suburban households use for food and shelter can be used by the rural households for other needs. Which of the following inferences is best supported by the statement made above?
(A) The average rural household includes more people than does the average urban or suburban household.
(B) Rural households have lower food and housing costs than do either urban or suburban households.
(C) Suburban households generally have more purchasing power than do either rural or urban households.
(D) The median income of urban and suburban households is generally higher than that of rural households.
(E) All three types of households spend more of their income on housing than on all other purchases combined.
                Ans: (B)

3.       Jose is a student of horticulture in the University of Hose. In a horticultural experiment in his final year, 200 seeds were planted in plot I and 300 were planted in plot II. If 57% of the seeds in plot I germinated and 42% of the seeds in plot II germinated, what percent of the total number of planted seeds germinated?
Ans: 48%
Plot 1 --- 57% out of 200 seeds germinated -> 114 seeds germinated.
Plot 2 --- 42% out of 300 seeds germinated -> 126 seeds germinated.
Thus totally 114 + 126 -> 240 seeds out of total 500 seeds germinated.
Hence the percentage is 240 * 100/500 -> 48%

4.       A closed cylindrical tank contains 36 pie cubic feet of water and it is filled to half its capacity. When the tank is placed upright on its circular base on level ground, the height of water in the tank is 4 feet. When the tank is placed on its side on level ground, what is the height, in feet, of the surface of the water above the ground?
Ans: 3 feet.
It should be noted that since the cylindrical tank is half filled to its capacity, when placed on its side also it will be filled to half its capacity.
Volume of the water in the cylinder in upright position is (pir2h). This is equal to 36pi.
Thus we have an equation pir2h = 36pi.
We are given ‘h’ is equal to 4. Applying this value we will have r2 = 9 and r = 3. ie half the base.
When the cylinder is placed on its side the water level will be only upto this height.
Hence the answer is 3 feet.

5.       The present ratio of students to teachers at a certain school is 30 to 1. If the student enrollments were to increase by 50 students and the numbers of teachers were to increase by 5, the ratio of the teachers would then be 25 to 1.What is the present number of teachers?
Ans: 15
Let ‘s’ be the initial number of students and ‘t’ the initial number of teachers.
Then we have the ratio s/t = 30/1. ->  s = 30t.
After 50 students and 5 teachers join the new ratio becomes –>  s+50/t+5 = 25/1
Substituting the value of  ‘s’ as 30t
We have a new equation->  30t + 50 = 25t + 125. Solving, we get the value of ‘t’ as 15.
Hence, the numbers of teachers initially were 15.

6.       College T has 1000 students. Of the 200 students majoring in one or more of the sciences, 130 are majoring in Chemistry and 150 are majoring in Biology. If at least 30 of the students are not majoring in either Chemistry or Biology, then the number of students majoring in both Chemistry and Biology could be any number from…..
Ans: between 110 and 130

Total students majoring in Sciences = 200
Students majoring in Chemistry        = 130
Students majoring in Biology             = 150
               Students majoring in both  ->  130 + 150 – 200 -> 80
                Students not majoring in Chemistry or biology = 30
                Thus students majoring in both Chemistry and Biology -> 80 + 30 = 110.
                Since the number of students majoring in Chemistry is only 130
                We could assume the range as between 110 and 130 for students majoring in both.

7.       Kelly and Chris are moving into a new city. Both of them love books and thus packed several boxes with books. If Chris packed 60% of the total number of boxes, what was the ratio of the number of boxes Kelly packed to the number of boxes Chris packed?
Ans: 2 : 3
An easy question to answer. If Chis had packed 60% of the boxes then Kelly would have packed the remaining 40% of boxes. Thus the ratio of boxes packed by Kelly and Chris is 40% : 60% or 2 : 3.

8.       A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction. Which of the following, if true, most seriously weakens the argument above?
(A)   The drug made from ibora bark is dispensed to doctors from a central authority.
(B)   The drug made from ibora bark is expensive to produce.
(C)   The leaves of the ibora are used in a number of medical products.
(D)   The ibora can be propagated from cuttings and grown under cultivation.
(E)    The ibora generally grows in largely inaccessible places.
Ans: (D)

9.       Machine A produces bolts at a uniform rate of 120 every 40 second, and Machine B produces bolts at a uniform rate of 100 every 20 seconds. If the two machines run simultaneously, how many seconds will it take for them to produce a total of 200 bolts?
Ans: 25 seconds

Machine A in 40 seconds produce 120 bolts. Ie in one second it produces 3 bolts.
Machine B in 20 seconds produce 100 bolts. Ie in one second it produces 5 bolts.
Thus in one second both A & B would produce 3 + 5 = 8 bolts.
Hence to produce 200 bolts both A & B would take 200/8 = 25 seconds.

10.   Wood smoke contains dangerous toxins that cause changes in human cells. Because wood smoke presents such a high health risk, legislation is needed to regulate the use of open-air fires and wood burning stoves.
Which of the following, if true, provides the most support for the argument above?
(A) The amount of dangerous toxins contained in wood smoke is much less than the amount contained in an equal volume of automobile exhaust.
(B) Within the jurisdiction covered by the proposed legislation, most heating and cooking is done with oil or natural gas.
(C) Smoke produced by coal-burning stoves is significantly more toxic than smoke from wood-burning stoves.
(D) No significant beneficial effect on air quality would result if open-air fires were banned within the jurisdiction covered by the proposed legislation.
(E) In valleys where wood is used as the primary heating fuel, the concentration of smoke results in poor air quality.
Ans: (E)







  


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