Question Number 88439 by otchereabdullai@gmail.com last updated on 10/Apr/20
$$\mathrm{kofi}\:\mathrm{have}\:\mathrm{three}\:\mathrm{books}\:\mathrm{on}\:\mathrm{his}\:\mathrm{desk},\:\mathrm{they} \\ $$$$\mathrm{are}\:\mathrm{mathematics}\:,\:\mathrm{biology}\:\mathrm{and}\:\mathrm{physics}. \\ $$$$\mathrm{Ama}\:\mathrm{also}\:\mathrm{have}\:\mathrm{three}\:\mathrm{books}\:\mathrm{on}\: \\ $$$$\mathrm{her}\:\mathrm{desk}\:\mathrm{namely}\:\mathrm{physics}\:,\mathrm{mathematics} \\ $$$$\mathrm{and}\:\mathrm{chemistry}.\:\mathrm{A}\:\mathrm{thief}\:\mathrm{picked}\:\mathrm{one}\:\mathrm{book} \\ $$$$\mathrm{from}\:\mathrm{each}\:\mathrm{of}\:\mathrm{their}\:\mathrm{desk}.\:\mathrm{what}\:\mathrm{is}\:\mathrm{the} \\ $$$$\mathrm{probability}\:\mathrm{of}\:\mathrm{picking}\:\mathrm{mathematics}\: \\ $$$$\mathrm{book} \\ $$
Commented by mr W last updated on 10/Apr/20
$${way}\:\mathrm{1}: \\ $$$${probability}\:{of}\:{picking}\:{M}\:{from}\:{M},{B}\: \\ $$$${and}\:{P}\:{by}\:{Kofi}\:{is}\:{p}_{\mathrm{1}} =\frac{\mathrm{1}}{\mathrm{3}}. \\ $$$${probability}\:{of}\:{picking}\:{M}\:{from}\:{P},{M}\: \\ $$$${and}\:{C}\:{by}\:{Ama}\:{is}\:{p}_{\mathrm{2}} =\frac{\mathrm{1}}{\mathrm{3}}. \\ $$$${probability}\:{of}\:{picking}\:{M}\:{both}\:{by}\:{Kofi} \\ $$$${and}\:{by}\:{Ama}\:{is}\:{then} \\ $$$${p}={p}_{\mathrm{1}} ×{p}_{\mathrm{2}} =\frac{\mathrm{1}}{\mathrm{3}}×\frac{\mathrm{1}}{\mathrm{3}}=\frac{\mathrm{1}}{\mathrm{9}} \\ $$$$ \\ $$$${way}\:\mathrm{2}: \\ $$$${to}\:{pick}\:{a}\:{book}\:{by}\:{Kofi}\:{there}\:{are}\:\mathrm{3} \\ $$$${possibilities}\:{and}\:{to}\:{pick}\:{a}\:{book}\:{by} \\ $$$${Ama}\:{there}\:{are}\:\mathrm{3}\:{possibilities},\:{totally} \\ $$$${there}\:{are}\:\mathrm{3}×\mathrm{3}=\mathrm{9}\:{possibilities}. \\ $$$${to}\:{pick}\:{the}\:{M}\:{book}\:{both}\:{by}\:{Kofi}\:{and} \\ $$$${by}\:{Ama}\:{there}\:{is}\:\mathrm{1}\:{possibility}. \\ $$$${the}\:{probability}\:{is}\:{then} \\ $$$$\Rightarrow{p}=\frac{\mathrm{1}}{\mathrm{9}} \\ $$
Commented by otchereabdullai@gmail.com last updated on 10/Apr/20
$$\mathrm{Prof}\:\mathrm{W}\:\mathrm{i}\:\mathrm{dont}\:\mathrm{know}\:\mathrm{the}\:\mathrm{word}\:\mathrm{to}\: \\ $$$$\mathrm{discribe}\:\mathrm{you}\:!\:\mathrm{all}\:\mathrm{what}\:\mathrm{i}\:\mathrm{will}\:\mathrm{say}\:\mathrm{is}\:\mathrm{God}\: \\ $$$$\mathrm{bless}\:\mathrm{you}\:\mathrm{and}\:\mathrm{protect}\:\mathrm{you}\:\mathrm{for}\:\mathrm{us}\:. \\ $$$$\mathrm{because}\:\mathrm{you}\:\mathrm{are}\:\mathrm{so}\:\mathrm{special}\:.\mathrm{i}\:\mathrm{alway}\: \\ $$$$\mathrm{pray}\:\mathrm{for}\:\mathrm{long}\:\mathrm{life}\:\mathrm{for}\:\mathrm{you} \\ $$$$ \\ $$
Commented by mr W last updated on 10/Apr/20
$${thank}\:{you}\:{sir}! \\ $$
Commented by Ar Brandon last updated on 10/Apr/20
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