enigma123 wrote:

Working alone at its own constant rate, a machine seals k cartons in 8 hours, and working alone at its own

constant rate, a second machine seals k cartons in 4 hours. If the two machines, each working at its own

constant rate and for the same period of time, together sealed a certain number of cartons, what percent of

the cartons were sealed by the machine working at the faster rate?

Can someone please tell me whether I have done this correctly as answer is not given?

Sol : Let say k =32

Rate of 1st machine = 32/8 = 4 cartons/hr

Rate of 2nd machine = 32/4 = 8 cartons/hr

%ge of cartons sealed by 2nd machine = 8/32*100= 25%

The best way to solve this question is to freeze the number of cartons generated at a perticular time, Say after 8 hrs.

For example - if i calculate the total number of cartons generated after 8 hours -

total number of cartons generated after 8 hours from 1st Machine = k cartons

total number of cartons generated after 8 hours from 2nd Machine = 2k cartons

Obviously, machine working at the faster rate is 2nd machine. hence, 2k/3k = 66.66%

You can try this with 4 hrs and 16 hours also.

Hope it helps.

Cheers!

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