The integer E has a tens digit of 6 and a units digit of 7. The units digit of integer y is 8. The product of E and y has a tens digit of 8. Which of the following is a possible tens digit of integer y?	Choose one:
A) 3  B) 4  C) 5  D) 6  E) 7
Let E be 67 and y be a8. Then the product of E and y can be written as (60+7)*(10a+8)=600a + 480+70a+56=600a+536+70a. Since 600a dose not affect on the tens digit we can ignore 600a.   So tens digit should be the unit of 3+7a. That means 3+7a =8, 18, 28, 38, 48 or 58 (since 3+7a&lt;=3+7*9= 
<gadget id="calculator">3+7*9</gadget>
<output>66</output>
66) ---&gt;7a=5, 15, 25, 35, 45, 55. So the only possibility is a=5.   So the answer is (5).
<result>C</result>
The integer E has a tens digit of 6 and a units digit of 7. The units digit of integer y is 8. The product of E and y has a tens digit of 8. Which of the following is a possible tens digit of integer y?