80%=.8
40*.8=32
32 people made their purchases with credit cards.
Answer:
11/13
Step-by-step explanation:
198/234
(198/18)/(234/18)
11/13
Answer:
The number of different combinations of three students that are possible is 35.
Step-by-step explanation:
Given that three out of seven students in the cafeteria line are chosen to answer a survey question.
The number of different combinations of three students that are possible is given as:
7C3 (read as 7 Combination 3)
xCy (x Combination y) is defines as
x!/(x-y)!y!
Where x! is read as x - factorial or factorial-x, and is defined as
x(x-1)(x-2)(x-3)...2×1.
Now,
7C3 = 7!/(7 - 3)!3!
= 7!/4!3!
= (7×6×5×4×3×2×1)/(4×3×2×1)(3×2×1)
= (7×6×5)/(3×2×1)
= 7×5
= 35
Therefore, the number of different combinations of three students that are possible is 35.
10 1/2-4 1/4= 6 1/4. 6 1/4-3 2/3= 2 7/12. They used 2 7/12 ft or 2ft 7in of wood to fix the stairs.
