You could use basic logic here instead of going for calculations.

Firstly, the given time taken to assemble a trainset is t minutes. Question asks for the total time in hours. So, you need to divide by 60 and not multiply by 60. Eliminate B, D, and E.

We need to choose b/w A and C. If only 1 worker assembles 5000 trainsets, the total time taken will be 5000*t/60 hrs. If there are n workers, then divide 5000*t/60 hrs by n. It's 5000*t / 60*n hours.

one doubt.

the problem says about average time.so the total time to assemble one trainset will be nt.so assembling 5000 sets would be 5000nt.
assume 10 people require average 5 min to assemble one set then total time required is 50 min.so 5000 sets would be 5000*50....right?

and sinced asked in hour so divide by 60

therefore i went for option 5000nt/60.

Please correct me.

saurabhmahajan wrote:one doubt.

the problem says about average time.so the total time to assemble one trainset will be nt.

Please correct me.

Hi,

I am afraid the flaw lies in this initial assumption. If there are 3 people who take an average of 5 minutes each to construct a train set, will we say that the total time to assemble one train set is 5 * 3 = 15 minutes ? Hence, the expression nt does not make much sense.

Hope this helps. Thanks.