The natural number 1 times 2 times 3 times 998 times 999 times 1000 has a zero at the end of the product

wrong
249 0
1000 divided by 5
1000 divided by 25
1000 divided by 125
1000 divided by 625
Integral part addition
two hundred and forty-nine

A car from a city to B city, the first third of the distance speed is 60 km / h, the middle third of the distance speed is 30 km / h, the last third of the distance speed is 20 dry meters / h, find the average speed of the car in the whole journey

1÷﹙1／3÷60+1／3÷30+1／3÷20）=30
The average speed of the car in the whole journey is 30 kilometers per hour

Given angle a, angle B = 3:2, and angle a = angle B = 180 ° find the degree of angle A and angle B

The answer is 180 / (2 + 3) = 36 * 2 = 72 degrees, 36 * 3 = 108 degrees

Uncle Wang drove from a to B. when he started, his speed was one ninth higher than the planned speed. As a result, he was 1.5 hours ahead of schedule
When returning, first drive 280 kilometers at the original speed, then increase the speed by one sixth, so arrive two hours ahead of time. How many kilometers is the distance between AB and Beijing

Original planned time: 1 / 9 + 1.5 = 15 hours
For the distance beyond 280km, if the original speed is adopted, the following requirements shall be met:
2 △ 1 / 6 + 2 = 14 hours
Then the original speed of 280 km, time: 15-14 = 1 hour
The original speed was 280 km / h (15-14) = 280 km / h
AB distance: 280 × 15 = 4200 km
PS: Data... The car is speeding

3a-2[5a+(3/2a-1)]

3a-2[5a+(3/2a-1)]
=3a-2[5a+3/2a-1]
=3a-10a-3/a+2
=-7a-3/a+2

The speed ratio of the express train and the local train is 3:2. After six hours, they meet and continue to move on
How many hours before the local train?

Set the express speed to 3x
Idle speed 2x
Distance between a and b y
Meet 3x * 6 + 2x * 6 = y = 30x after driving for 6 hours
Express time Y / 3x = 30 / 3 = 10
Idle Y / 2x = 30 / 2 = 15
The express train is five hours earlier than the local train

X ^ - y ^ = 16 rectangular coordinates into polar coordinates equation

X = ρ cos θ, y = ρ sin θ, then:
x²－y²=16
(ρcosθ)²－(ρsinθ)²=16
ρ²(cos²θ－sin²θ)=16
ρ²cos2θ=16

There is a batch of cement in a construction site. 40% of it is transported in the first day, and 35% of it is transported in the second day. There are still 17 tons left. How many tons of this batch of cement workers?

100%-（40%+35%)=25%
100%/25%=4
17 × 4 = 68 (T)

Given that m, N, P and Q are the midpoint of BC, AC, OA and ob respectively in the space quadrilateral oabc, if AB = OC, we prove that PM is vertical QN

Because PQ is the median line of triangle OAB, PQ = AB / 2
Similarly, Mn = AB / 2, PN = OC / 2, MQ = OC / 2
Because AB = OC, so PQ = PN = Mn = QM, so the quadrilateral pnmq is diamond, so PM is vertical to QN

Two piles of yellow sand are 5.7 tons in total. 34 tons are used in the first pile and 35 tons in the second pile. The remaining two piles are 15 tons less than the first pile. How many tons are there in the first pile?

Set the first pile as unit "1". The first pile uses 34, and there are still 14 left. The second pile uses 35, and there are still 25 left. Together, the second pile is the first pile: 1-15-14 = 1120, that is, 25 of the second pile is equivalent to 11201120 △ 25 = 118 of the first pile, that is, the second pile is equivalent to 118 of the first pile, 5.7 △ 1 + 118, = 5

The natural number 1 times 2 times 3 times 998 times 999 times 1000 has a zero at the end of the product