std 12 itihas | ch 2 | 18મી સદીનો ઉત્તરાર્ધ અને સત્તાપ્રાપ્તિ માટે સંઘર્ષ | part 2 | vijay sir

The roots of equation x^2+2(a-3)x+9=0 lie between -6 and 1 and 2, h_1, h_2, …, h_20 [a] are in H.P., where [a] denotes the integeral part of a and 2,a_1,a_2,..a_20 [a] are in A.P. then a_3h_18= (A) 6 (B) 12 (C) 3 (D) none of these

A sealed box was found which stated to have contained alloy composed of equal parts by weight of two metals A and B . These metals are radioactive, with half lives of 12 years and 18 years. Respectively and when the container was opened it was found to contain 0.53 kg of A and 2.20 kg of B . The age of the alloy is Mxx10+n then find M-n

Over the past 200 working days, the number of defective parts produced by a machine is given in the following table : |{:("Number of","0 1 2 3 4 5 6 7 8 9 10 11 12 13"),("defective parts",),("Days","50 32 22 18 12 12 10 10 10 8 6 6 2 2"):}| Determine the probability that tomorrow's output will have : (i) no defective part. (ii) at least one defective part, (iii) not more than 5 defective parts, (iv) more than 13 defective parts.

Median of a distribution is the value of the variable which divides it into equal parts . In case of individual observations x_1,x_2 .. x_n , if the number of observations is odd, then median is the value of ((n+1)/2) th observation when the observations have been arranged in ascending or descending order of magnitude. In case of even number of observations median is the A.M. of the values of (n/2) th and (n/2+1) th observations, arranged in ascending or descending order of magnitude . The mode of distribution is that value of the variable for which the frequency is maximum . Median of the distribution 25,20,11,3,12,18,17 ,9,21,22 is

Median of a distribution is the value of the variable which divides it into equal parts . In case of individual observations x_1,x_2 .. x_n , if the number of observations is odd, then median is the value of ((n+1)/2) th observation when the observations have been arranged in ascending or descending order of magnitude. In case of even number of observations median is the A.M. of the values of (n/2) th and (n/2+1) th observations, arranged in ascending or descending order of magnitude . The mode of distribution is that value of the variable for which the frequency is maximum . The mode of following series is {:("value (x)",40,44,48,52,56,62,64,72,76),("frequency (f)",10,12,14,20,15,19,18,8,4):}

When Vijay sells 12 pens, he gains the selling price of 2 pens . Calculate his % profit A. 15% B. 20% C. 18% D. 12%

Stearic acid [CH_(3)(CH_(2))_(16)CO_(2)H] is a fatty acid the part of fat that stores most of the energy .1.0 g of Stearic acid was burnt in a bomb calorimeter . The bomb had capacity of 652 J//^(@)C . If the temperature of 500 g water rose from 25.0 to 39.3^(@)C how much heat is released when the stearic acid was burned? ["Given "C_(p)(H_(2)O)=4.18J//g^(@)c]

a. When 4.2 g NaHCO_(3) is added to a solution of CH_(3)COOH is released into atomosphere. The residue is the found to weigh 12.0g . Show that these observations are in agreement with the low of conservation of weigh. b. If 6.3 g of NaHCO_(3) are added to 15.0 g CH_(3)COOH solution. The residue is found to weigh 18.0 g what is the mass of CO_(2) released in this reaction?