Explanation

LCM of 1/10 + 1/40 = 1/8

Number of days to complete the total work = 8 days

Explanation

3 persons can do 3 jobs in 3 days

1/3 of the work will take 1/3 of the time, so

3 people can do 1 job in 1 day

It will take 1 person 3 times as long, so

1 person can do 1 job in 3 days

7 persons can do 7 times the work in the same time, so

7 persons can do 7 jobs in 3 days

Explanation

The length of cloth painted by one man in one day = 48 / 4 x 2 = 6 m 

No. of days required to paint 36 m cloth by 6 men = 36 / 6 x 6 = 1 day

Explanation

Clearly, the number of trees in the row =(4+1+4)=9.

Explanation

Now Maryam was shifted to 4 places to the right.

This implies her place is x+4 from left now, but it is given that her new place is 12th from left.

Now, in a row of 21 girls, her place is 8,

which is 14th place from right.

Explanation

The logic followed here is:

Saqib ranks seventh from the top and twenty-eight from the bottom in the class

Number of students in the class= 7 + 28 -1 

                                                        =  34

Explanation

Total no. of students = Top position + Bottom position - 1

Total no. of  students =16+49−1

                                      = 64

****

Number of students in the class $=(15+1+48)=64$

Explanation

50 - ( 10 + 25 ) = 15 

Khadija is middle of  15

= 8 + 10 

= 18th

Explanation

Explanation

200 percent *800 

= ( 200:100)*800

= ( 200*800):100

=160000:100

= 1600