Question

[Hoàng Mai Xuân]

1.give N= 1x2x3x........x50.How many the last digits 0 are there

Answer 1

[Thám Tử THCS Nguyễn Hiếu]

Analyze all factors that really collect divisor is 5. We have:
1 × 5 = 5, 15 = 3 × 5, 25 = 5 × 5, 35 × 5 = 7, 45 = 9 × 5
10 = 2 × 5, 4 × 20 = 5, 30 = 6 × 5, 40 × 5 = 8, 50 = 2x5x5
In 10 charge on all 12 factors 5
Each factor of 5 to 1 that's another even number of administration will have to take the first digit 0
So take advantage of administration area for Bag 12 digits 0

Answer 2

[_ FTBOYS_]

Analyze all factors that really collect divisor is 5. We have: 1 × 5 = 5, 15 = 3 × 5, 25 = 5 × 5, 35 × 5 = 7, 45 = 9 × 5 10 = 2 × 5, 4 × 20 = 5, 30 = 6 × 5, 40 × 5 = 8, 50 = 2x5x5 In 10 charge on all 12 factors 5 Each factor of 5 to 1 that's another even number of administration will have to take the first digit 0 So take advantage of administration area for Bag 12 digits 0