Question

write any 3 rational numbers between -2 and 0 -class 8



on a farm 3/7 of the cows were black while 28 were white.
a- find the total number of cows
b- find the number of black cows

Answer 1

-1÷2,-1÷3
a=12
b=444444444444444444444444

Answer 2

-2/2, -2/4,-2/6
a - let total number of cows be x
according to question
3/7x +28 = x
3/7x = x-28
3/7x -x/1 = -28
LCM of 7 and 1 = 7
3/7x - 7/7x = -28
-4/7x = -28

7x = -28 ÷ -4
x = -28 ÷ -4/7
x = -28 × -7/4
x = 49
b - number of black cows
= 3/7 of total number of cows
= 3/7 × 49
= 21