1. For a nonnegative interger n, if the remainder is 1 when 2^n is divided by
3, then which of the following must be true?(多選)
A. n is greater than 0
B. 3^n=(-3)^n
C. 根號2^n is an integer
2. If y is inversely proportional to x and y is 15 when x=5, what is the
value of y when x=25?
我是算y:x=15:5=75:25 故y=75.
但答案是y=3, 請問是我哪邊理解錯了？
3. {a,b} represents the remainder when a is divided by b.
c and d are positive intergers with c<d.(比大小)
A: {c,d}
B: {d,c}
4. If p and q are primes greater than 2, which of he following must be true?
(多選)
A. p+q is even
B. pq is odd
C. p^2+q^2 is even
D. 4p-q is even
E. p/2+q/2 is even
5. 這題我真的有看沒有懂...
Pat drove from his home to school at 60 miles per hour. Returning over the
same route, there was a lof of traffic, and he was only able to drive at
40 miles per hour. If the return trip took 1 hour longer, how many miles
did he drive for the round trip? (填空)
先謝過板上高手了