Sejal Jain

CAT Preparation Community 6y ago

Working alone A can do a work in 72 days and B in 90 days. If they work on it together for 10 days,then what fraction or work is left?

5

sandeep kumar 6y ago

3/4 th work is left

ANUGRAH ANUGRAH 6y ago

Any method for finding it ?

Chanchal Rao 6y ago

@Anugrah A = 72 = 1.38( per day efficiency ) B = 90 = 1.11( per day efficiency ) 1.38+1.11 = 2.49 so , 2.49* 10 = 24.9 24.9 - work complete out of 100 so , total 75 approx work is pending & 3/4 is the ratio of 75.

Winter Scott 6y ago

Hi Sejal, Consider that A and B make cakes. The work is to make 360 cakes(LCM of 72 and 90). Thus, individually A makes 5 cakes in a day and B makes 4 cakes a day. In 10 days they make 90 cakes. Hence fraction left is (360-90)/360 which is 3/4.

Aditya Chikte 6y ago

lcm of 72 and 90= 360, a' s one day work 360/72=5, b's one day work 360/90= 4 units in 10 days together 10(5+4)= 90, remaining units 270, which is 270/360 fraction= 3/4th of total work

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