Question

Express each of the follwoing sets in set-builder notation (form):

(viii) $\{42,49,56,63,70,77\}$

Answer 1

Step: Expressing the given set in set-builder form

In set builder method the actual elements of the set are not written, but a rule or a statement or a formula is written in the briefest possible way

$\text{Given set}\{42,49,56,63,70,77\}$

As 42, 49, 56, 63, 70, 77 are multiple of 7, we can see that the elements of given set are numbers divisible by 7 form 42 to 77.

Hence, the set-builder form is $\{x:x\text{is divisible by 7 and}42\le x\le 77\}$