Question
There are three classes P, Q and R. The average marks of
class P is 75. The average marks of class Q is 80. The average marks of class R is 85. The average marks of class P and Q is 77, the average marks of class Q and R is83. Find the approximate average marks of three classes.Solution
By allegation method: 
So the ratio of students in class P to Q comes out to 3 : 2 & the ratio of students in class Q to Ris 2 : 3. Ratio of students in P, Q and R = 3 :2 : 3 So, average of all the classes = `(75xx3 + 80 xx2 + 85xx3)/(3+2+3)` = `(225+160+255)/8` = 80
Given below an equation having four blanks you have to check from the alternatives which among the given is correct?
21 _ 51 _ 7 _ 12 _ 75
After interchanging the given two signs, what will be the value of the given equation?
X and –
64 + 15 ÷ 90 - 120 X 17
Select the correct combination of mathematical signs that can sequentially replace the “@” sign and balance the following equation.
16@5@4@2@...
If the ‘-’ and ‘×’ are interchanged, What will be the value of the following equation?
34 × 22 + 192 ÷ 12 – 8
...Which among the given operators should replace the “%” (in the same order) in the given expression below:
5 % 10 % 5 % 36 % 15 % 6
What will be the value of expression if the numbers/digits ‘(30)’ and ‘(13)’ are interchanged?
78 ÷ 30 × 6 + 13 - 14 + 12
...Select the correct combination of mathematical signs that can sequentially replace the sign * and make the equation correct.
3 * 12 * 4 * 5 * 4 * 116
Out of the total number of players, 100/3 % are in hotel X and the remaining are in hotel Y. If 20 players from hotel Y are shifted to hotel X, then the...
Which two signs need to be interchanged to make the following equation correct?
75 – 18 × 80 ÷ 16 + 40 = 125
Select the correct combination of the mathematical signs to replace the ‘@’ symbols in the below equation and thereby balance it:
81@9@5@30@1...
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