Question

कौन सा प्रदूषण ज्यादा खतरनाक है 1 वायु प्रदूषण 2 जल प्रदूषण 3 औद्योगिक प्रदूषण 4 ध्वनि प्रदूषण?

Answer 1

Using LCM method you can solve this question in the following manner-

GIVEN :-

A & B together takes 6 days and A alone takes 15 days to complete the work

we can write it as -

A+B = 6

A= 15

Now finding total unit work by taking LCM of 6 & 15 which is 30

Total unit work = 30

Now finding unit work completed in 1 day by dividing total unit work by their respective 1 day work

Unit work done in 1 day-

A+B=30/6=5 ——-(1)

A=30/15=2 ——-(2)

Putting value of A in eq. (1) we get

B=3

Now for finding total days required by them to complete the whole work alone we will divide the total unit work their respective 1 day work-

Hence total days required by B to complete the whole work alone is-

30/3=10 days

3