Question
The average weight of certain number of students in a
class is 72 kg. 8 students whose average weight is 75 kg left the class and 3 students whose average weight is 90 kg join the class, because of which the average weight of the class increases by 0.75 kg. Find the total number of students in the class initially.Solution
Let, the total number of students in the class initially be 'x'.Total weight of the class initially = 72 X x = '72x' kgNew total weight of the class = 72x - 8 X 75 + 3 X 90 = 72x - 600 + 270 = 72x - 330 kgATQ,[(72x - 330) /(x - 5) ] = 72 + 0.75 = 72.75Or, 72x - 330 = 72.75 X (x - 5)Or, 72x - 330 = 72.75x - 363.75Or, 0.75x = 33.75Or, x = 45So, the number of students in the class initially were 45.
Statements: B ≥ U > P = E ≥ X; X > K > N ≥ J
Conclusions: I. N < P   II. J ≤ X
In the question, relationship between some elements is shown in the statements (s). These statements are followed by two conclusions. Read the statemen...
In the question, assuming the given statements to be true, find which of the conclusion (s) among given two conclusions is /are definitely true and the...
Which of the following set of symbols should be placed in the blanks respectively (from left to right) in the given expression in order to make the expr...
Statements: S = T, U < L, V ≥ S, T ≤ U
Conclusion:
I. T ≤ V
II. L > T
Which among the following symbols should replace the question mark [?] (in the same order from left to right) in the given expression in order to make b...
In the question, assuming the given statements to be true, find which of the conclusion (s) among given three conclusions is/are definitely true and th...
Statements: A > Y = D > Q, M ≤ B > P > Y
Conclusion:
I. Y ≤ M
II. B > QÂ Â
In the question, assuming the given statements to be true, find which of the conclusion (s) among given two conclusions is/are definitely true and then...
Statements: G@B; W#Z; B%W
Conclusions:
I) G@Z
II) Z@B
Relevant for Exams:
