How do you figure 12 is 30% of what number

X times .3=12 So X equals 12/.3 which is 40. Another way of solving it is dividing 12 by 3 which is 4 then multiply by ten.

12 / 0.30 =40 so the number is 40

He should collect all the good reasons why having a smart phone can be useful . On a piece a paper her can write all the good reasons . Which can be making an emergency call if anything , calling the police or using the internet to google important questions