help

jannyguo

If integer k is equal to the sum of all even multiples of 15 between 295 and 615, what is the greatest prime factor of k?
5

7

11

13

17

jannyguo

Lindsay can paint 1/x of a certain room in one hour. If Lindsay and Joseph, working together at their respective rates, can paint the room in one hour, what fraction of the room can Joseph paint in 20 minutes?
1

3x


x

x – 3


x – 1

3x


x

x – 1


x – 1

x

wwc008love

选C吧。。。
295/15=19又2/3....615/15=41....so all even multiples of 15 between 295 and 615 are "20,22,24......40"
the sum of all even multiples of 15 between 295 and 615=11*(20+40)/2=11*3*5*2
the greatest prime factor of k=11

jannyguo

If n is a non-negative integer such that 12n is a divisor of 3,176,793, what is the value of n12 – 12n ?
- 11
- 1
0
1
11

jannyguo

How many factors does 362 have?
2
8
24
25
26

jannyguo

How many factors does 36^2 have?
2
8
24
25
26

jannyguo

If n is a non-negative integer such that 12^n is a divisor of 3,176,793, what is the value of n^12 – 12^n ?
- 11
- 1
0
1
11

jannyguo

thanks a lot, i do not even understand the questions.....I thought math was ok, but I did not realize that it is not easy... Good luck, dear friend