Question
The average of two numbers ‘X’ and ‘Y’ is 400
such that they are in the ratio 3:5 respectively. Another number ‘Z’ is 80 more than ‘Y’ and fourth number ‘W’ is 10% of the ‘X’. Find the average of ‘Z’ and ‘W’.Solution
Sum of ‘X’ and ‘Y’ = 400 × 2 = 800
Therefore,
‘X’ = 800 × (3/8) = 300
‘Y’ = 800 – 300 = 500
‘Z’ = 500 + 80 = 580
‘W’ = 0.1 × 300 = 30
Required average = {(580 + 30)/2} = 305
The minimum value of 45 sin2 θ + 28 cos2 θ is

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