Help with a math/percentage question please!?

x + .11x = 490

x(1 + .11) = 490

1.11x = 490

x = 490/1.11

x = 441.44144144144144144144144144144

about 441 women were pregnant in 1999

Take the total 490 x 10% = 49 - 441 x11% = 48.51 + 441 = 486.51 round up to next number equals 490 there for 441 people were pregnant in 1999

It's easy to do 10% & 1%...

1/10 is 49

& 1/100 is 4.9

...they add up to 53.9 [11%]

...but this doesn't help because it's 11% of the unknown number that has been added on to make 490.

So the sum is for 100% (called 'n') + 11% expressed as 'x 1.11',

n x 1.11 = 490

...to find n, we turn the sum around;

490 / 1.11 = n

and this gives the value 441.4414414414414

which is 441 to the nearest 'whole person'

...to check this, we can go back to the top of the answer and use the simple 10 + 1 %s

10 % of 441 is 44.1

1% is 4.41

they add up to 48.51 (11%)

so, 441 + 48.51 = 489.51

...which to the nearest whole person, is 490 :)