IBPS SO Prelims Exam Model Paper 4

GIVEN:
(i) Time taken by Seema to make a bundle of roties = 12 minutes,
(ii) Time taken by Samir to make a bundle of roties = 15 minutes,
(iii) Time taken by them together to complete a work = 10 minutes.
FORMULA USED:
(i) Time to complete the full work × 1-day work = Total work
CONCEPT:
(i) Total work can be assumed as any multiple of L.C.M. of a separate timing.
CALCULATIONS:⇒ Together they can make 9 roties in a minute if a total roties are 60 in a bundle.
⇒ Time taken by them together to make 60 roties = 60/9 minutes.
⇒ But they are taking 10 minutes to make 60 roties.
⇒ Which means, they are making 6 roties in a minute. i.e. 3 roties fewer than working at full capacity.
⇒ They are making 3 fewer roties in every 60 roties bundle.
⇒ Actuality, they are making 6 fewer roties, which means 120 roties in the bundle.
∴ The bundle will have 120 roties in it.