Question

'K' stands for a whole number.'K' + 7 is greater than 100.'K' - 7 is less than 90.List all the numbers that 'K' could be.

Answer 1

93<k<97-> K=94 or 95 or 96

Answer 2

K + 7 > 100 k - 7< 90

subtract 7 from bot sides add 7 to both sides
k > 93 K<97

then 93< K < 97

K could be 94, 95 or 96

Answer 3

First specification k+7>100, then k>93. Now consider the second specification K-7<90 tells us that K<97. If we wish to meet both specifications, 93<K<97. Since K is an integer, \[K \in \left\{ 94,95,96 \right\}\]as noted above.