Question
There are 15 numbers such that average of first 12
numbers is 80 while the average of last five numbers is 110. Find the 12th number, if the ratio between 11th and 12th number is 13:7, respectively.Solution
Sum of first 12 numbers = (12 x 80) = 960 Sum of last 5 numbers = (110 x 5) = 550 Sum of 11th and 12th number = (960 - 550) = 410 So, 12th number = 410 x (7/20) = 143.5
If 2x + (1/9x) = 5, then find the value of 81x2 + (1/4x2) - (1785/4)
‘a’ is directly proportional to ‘b’. If at a=30, the value of ‘b’ is 20% greater than ‘a’, then find the value of ‘a’ when b=54.
...(288 ÷ 8)² × (144 ÷ 24)³ = 24 × ? × (51840 ÷ 20)
((99.9 - 20.9)² + (99.9 + 20.9)² )/(99.9 x 99.9 + 20.9 x 20.9) = ?
...
If a = 32, b = c = 31, then find the value of a 3 + b 3 + c 3 – 3abc.
If a = 2 + √3, then the value of (a6 + a4 + a2 + 1)/a3 is
Calculate the value of the expression: {2 X (P3 - Q3) - 30 X P X Q} if (P - Q) = 6 and (P2 + Q2) = 80
when x =4 and y =-6 then find the value of 27x³ +58x²y +31xy² +8y³?
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