Question

A rectangular field has dimensions $100m\times 80m$. Three cyclists start together and can cycle $24m,30m$, and $36m$, per minute, round the field. After how much time all the cyclist meet again at the starting point.

• A. $1m$
• B. $1day$
• C. $1hr$
• D. $1sec$

Answer 1

The correct option is C $1hr$

Given the dimensions of the rectangular field is $100m\times 80m$.

Then the perimeter of the field is $2(100+80)=360$ m.

Now time taken by the cyclists to found the field are $\frac{360}{24}=15$,$\frac{360}{36}=10$,$\frac{360}{30}=12$ minutes.

So they will meet after the time of $LCM$ $(15,10,12)=60$ minutes $=1$ hr. of starting.