day4作业

1.

numbers = 1
for i in range (0,20):
    numbers *= 2
print (numbers)
'''
求2的20次方的值
'''
print (2**20)

2.

summation = 0
num = 1
while num <= 100:
    if (num %3 == 0 or num %7 == 0) and num %21 != 0:
        summation += 1
    num += 1
print (summation)
'''
求在1到100的数中，既能被3,7整除，又不能被21整除的数有多少个
'''

3.求1到100之间所有数的和、平均值

# for
sum = 0
x = 1
for x  in range (1,101):
    sum += x
print ('1-100的和：%d,平均值:%.2f' % (sum,sum/100))

# while
x = 1
sum = 0
while x <=100:
    sum += x
    x += 1
print （'1-100的和：%d,平均值:%.2f' % (sum,sum/100))

运行：

5050 2525.0
5050 2525.0

4.计算1-100之间能被3整除的数的和

# for
sum = 0
for x in range (1,101):
    if x %3 :
        continue 
    sum += x
print (sum)

# while
sum = 0
x = 1
while x <=100:
    if x %3 == 0:
        sum += x
        x += 1
print (sum)

运行：

1683
1683

5.计算1-100之间不能被7整除的数的和

# for
sum = 0
x = 1
for x in range (1,101):
    x += 1
    if x%7 != 0:
        sum += x
print (sum)


# while
sum = 0
x = 1
while x <= 100:
    x += 1
    if x %7 != 0:
        sum += x
print (sum)

运行：

4415
4415