It's 0 because 10+10 = 20 then subtract 20 and you get zero.
You can use models to help you divide by making the number of models as your divisor. For example let's say I am dividing 8 ÷ 2. So you would make 8 circles (doesn't have to be circle it can be whatever like squares) and then make groups of 2 until you run out of circles. Then how many groups there are is your answer. 8÷2=4. Hope I helped!
Answer:
c) it appears to be sound because the data are not biased in anyway.
Step-by-step explanation:
From the information given regarding the sample selection method , the size, the larger sample from which the survey subject were selected, we can conclude that the data is sound and not in anyway biased. The subject were selected from a reputable market research firm, which means the subjects were chosen from a larger sample which is reliable and not just a voluntary pool of subjects. Also, the selection process is randomized. Based on these, there are no flaws which are likely to cause the introduction of bias into the sample selected. Hence, the data is sound and not in any way biased.
