Answer: D) 29 yrs Explanation: Let the avg age of 7 boys be 'p' yearsLet the age of the girl be 'q' yearsFrom given data,The age of 7 boys = 7p yearsNow the new average = (p + 1) when 22 yrs is replaced by qNow the age of all 7 will become = 7(p + 1) yrsHence, 7p - 22 + q = 7(p + 1) yrs7p - 22 + q = 7p + 7q = 22 + 7 = 29 Therefore, the age of girl = q = 29 years.

Answer: B) 19/42 Explanation: A red ball can be drawn in two mutually exclusive ways  (i) Selecting bag I and then drawing a red ball from it.   (ii) Selecting bag II and then drawing a red ball from it.   Let E1, E2 and A denote the events defined as follows: E1 = selecting bag I, E2 = selecting bag II A = drawing a red ball Since one of the two bags is selected randomly, therefore  P(E1) = 1/2  and  P(E2) = 1/2 Now, PAE1 = Probability of drawing a red ball when the first bag has been selected = 4/7   PAE2  = Probability of drawing a red ball when the second bag has been selected = 2/6  Using the law of total probability, we have   P(red ball) = P(A) = PE1×PAE1+PE2×PAE2                              = 12×47+12×26=1942

Answer: C) 70% Explanation: Let C.P.= Rs. 100. Then, Profit = Rs. 320, S.P. = Rs. 420. New C.P. = 125% of Rs. 100 = Rs. 125New S.P. = Rs. 420. Profit = Rs. (420 - 125) = Rs. 295 Required percentage = (295/420) * 100 = 70%(approx)

Answer: B) 54055 Explanation: Here the given series follows a pattern that, multiplying the number with odd numbers in decreasing order starting with 13. That is,   6 × 13 = 78   65 × 11 = 858   858 × 9 = 7722   7722 × 7 = 54054   54054 × 5 = 270270   Hence, the wrong number is 54055

Answer: A) Z discs Explanation: A sarcomere is the basic unit of striated muscle tissue. It is the repeating unit between two Z lines. Skeletal muscles are composed of tubular muscle cells (myocytes called muscle fibers or myofibers) which are formed in a process known as myogenesis. Muscle fibers contain numerous tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as alternating dark and light bands. Sarcomeres are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or relaxes.   A muscle fiber from a biceps muscle may contain 100,000 sarcomeres.

Answer: C) 246 Explanation: A Committee of 5 persons is to be formed from 6 gentlemen and 4 ladies by taking.    (i) 1 lady out of 4 and 4 gentlemen out of 6  (ii) 2 ladies out of 4 and 3 gentlemen out of 6  (iii) 3 ladies out of 4 and 2 gentlemen out of 6  (iv) 4 ladies out of 4 and 1 gentlemen out of 6    In case I the number of ways = C14×C46 = 4 x 15 = 60  In case II the number of ways = C24×C36 = 6 x 20 = 120  In case III the number of ways = C34×C26 = 4 x 15 = 60 In case IV the number of ways = C44×C16 = 1 x 6 = 6    Hence, the required number of ways = 60 + 120 + 60 + 6 = 246

Answer: D) a puzzle box Explanation: Edward Thorndike (1874 - 1949) is famous in psychology for his work on learning theory that lead to the development of operant conditioning within behaviorism. Thorndike (1898) studied learning in animals (usually cats). He devised a classic experiment in which he used a puzzle box to empirically test the laws of learning.

Answer: B) 7.5 Explanation: The given number series follows a pattern that 11 11 - 5.5 = 5.5 5.5 + 4.5 = 10 10 - 3.5 = 6.5 6.5 + 2.5 = 9 9 - 1.5 = 7.5   Hence, the next number in the given number series is 7.5.