Menu Close

Question-134145




Question Number 134145 by EDWIN88 last updated on 28/Feb/21
Commented by Ñï= last updated on 28/Feb/21
Any time any 2 hands no coincide.I remember.
$${Any}\:{time}\:{any}\:\mathrm{2}\:{hands}\:{no}\:{coincide}.{I}\:{remember}. \\ $$
Commented by mr W last updated on 28/Feb/21
please explain what you mean sir!
$${please}\:{explain}\:{what}\:{you}\:{mean}\:{sir}! \\ $$
Answered by mr W last updated on 28/Feb/21
assumed the hands move uniformly.  say x minutes past 2.  position of hour hand: 10+(x/(60))×5  position of minute hand: x  10+(x/(60))×5=x  x=((120)/(11))=10((10)/(11))  ⇒(a)
$${assumed}\:{the}\:{hands}\:{move}\:{uniformly}. \\ $$$${say}\:{x}\:{minutes}\:{past}\:\mathrm{2}. \\ $$$${position}\:{of}\:{hour}\:{hand}:\:\mathrm{10}+\frac{{x}}{\mathrm{60}}×\mathrm{5} \\ $$$${position}\:{of}\:{minute}\:{hand}:\:{x} \\ $$$$\mathrm{10}+\frac{{x}}{\mathrm{60}}×\mathrm{5}={x} \\ $$$${x}=\frac{\mathrm{120}}{\mathrm{11}}=\mathrm{10}\frac{\mathrm{10}}{\mathrm{11}} \\ $$$$\Rightarrow\left({a}\right) \\ $$
Commented by mr W last updated on 28/Feb/21
old style clocks have hands which  don′t move uniformly, but stepwise,  see Q17449
$${old}\:{style}\:{clocks}\:{have}\:{hands}\:{which} \\ $$$${don}'{t}\:{move}\:{uniformly},\:{but}\:{stepwise}, \\ $$$${see}\:{Q}\mathrm{17449} \\ $$
Commented by EDWIN88 last updated on 28/Feb/21
yes..thanks
$$\mathrm{yes}..\mathrm{thanks} \\ $$
Answered by bobhans last updated on 28/Feb/21
∴The time when hands be together  = (5×n×((60)/(55))) mins past n o′clock  Here n=2  = 5×2×((60)/(55)) = ((120)/(11)) = 10 ((10)/(11)) mins past 2
$$\therefore\mathrm{The}\:\mathrm{time}\:\mathrm{when}\:\mathrm{hands}\:\mathrm{be}\:\mathrm{together} \\ $$$$=\:\left(\mathrm{5}×\mathrm{n}×\frac{\mathrm{60}}{\mathrm{55}}\right)\:\mathrm{mins}\:\mathrm{past}\:\mathrm{n}\:\mathrm{o}'\mathrm{clock} \\ $$$$\mathrm{Here}\:\mathrm{n}=\mathrm{2} \\ $$$$=\:\mathrm{5}×\mathrm{2}×\frac{\mathrm{60}}{\mathrm{55}}\:=\:\frac{\mathrm{120}}{\mathrm{11}}\:=\:\mathrm{10}\:\frac{\mathrm{10}}{\mathrm{11}}\:\mathrm{mins}\:\mathrm{past}\:\mathrm{2} \\ $$
Commented by EDWIN88 last updated on 28/Feb/21
thanks
$$\mathrm{thanks} \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *