GATE Questions

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The quadratic equation whose roots are reciprocal of 2x2+5x+3=0 can be obtained by replacing x by 1/x.

Hence, 2(1/x)(1/x)+ 5(1/x) + 3 = 0

=> 3x2+5x+2=0

The given number series 11, 12.2, 14.6, 18.2, ?

11

11 + 1.2 = 12.2

12.2 + 2.4 = 14.6

14.6 + 3.6 = 18.2

18.2 + 4.8 = 23

Hence, the next number in the given number series is 23.

The given number series is 1 8 36 ? 1100 7701

It follows a pattern that,

1

1 x 3 + 5 = 8

8 x 4 + 4 = 36

36 x 5 + 3 = 183

183 x 6 + 2 = 1100

1100 x 7 + 1 = 7701

Hence, the missing number in the given series is 183.

The sum of the oxidation numbers in a compound must equal zero. In the compound hydrogen sulfide, H2S, the two hydrogen atoms have an oxidation number of +1, for a total of +2.

Therefore, the oxidation number of sulfur in the compound is -2, and the sum of the oxidation numbers is 0.

The given series is 118, 166, 190, 202, 208, ?

118

118 + 48 = 166

166 + 24 = 190

190 + 12 = 202

202 + 6 = 208

208 + 3 = 211

Initialy from left 7th = kumar
from right 9th = pawan
Interchange kumar = 11th from left, from right kumar = 9th;
11+8 = 19;
8 is 1,2,3,4,5,6,7(pawan),8,9,10,11(kumar),12,13,14,15,16,17,18,19;
simply count the 9th place from right we will get total as 19.

Let number of boys = x  , Let number of girls = y
Total numbers of students = x + y
(x + y) × 15.8 = 16.4x + 15.4y
0.6x = 0.4y
x/y = 0.4/0.6 = 2/3

 Ratio of boys and girls in the class is 2:3