In calculating the mean of 8 numbers, a boy mistakenly us...
In calculating the mean of 8 numbers, a boy mistakenly used 17 instead of 25 as one of the numbers. If he obtained 20 as the mean, find the correct mean.
24
23
21
19
Correct answer is C
Let the sum of the 8 numbers = y.
\(\frac{y}{8} = 20 \implies y = 20 \times 8 = 160\)
\(160 - 17 = 143 (\text{the sum of the other 7 numbers})\)
\(mean = \frac{143 + 25}{8} = \frac{168}{8}\)
= 21
Find the locus of points which is equidistant from P(4, 5) and Q(-6, -1). ...
The sales of five salesgirls on a certain day are as follows; GH¢ 26.00, GH¢ 39....
The inverse of a function is given by \(f^{-1} : x \to \frac{x + 1}{4}\)....
Express \(\frac{8 - 3\sqrt{6}}{2\sqrt{3} + 3\sqrt{2}}\) in the form \(p\sqrt{3} + q\sqrt{2}\)...
Find \(\lim\limits_{x \to 3} \frac{2x^{2} + x - 21}{x - 3}\)....
If g : r \(\to\) 5 - 2r, r is a real number, find the image of -3...