What is 1/2 times 2/1, i need explenation​

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

What is the factored form of the following expressions? d^2 – 13d + 36

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6