Solution: 702 = 2× 13× 3× 3, and the prime factor is 2,13,3.
Two composite numbers must contain two or more prime factors.
Two complex numbers are coprime, that is, there is no common prime factor. So all the prime factors are in one number, leaving only two prime factors 2, 13.
So these two numbers are 3× 3× 3 = 27 respectively; 2× 13=26
(to solve this kind of problem, you can basically answer it according to the above process, of course, you should use it flexibly. )
A batch of notebooks were distributed to the whole class, with an average of each person 12 copies. Only for girls, with an average of 20 copies per person. If you divide it into boys, you can divide it into several parts.
Solution:1÷ (112-1/20) = 30 copies.
The total collection is regarded as "1", because each student is given 12 books on average, so the total number of people is equivalent to112 of the total collection.
Only for girls, with an average of 20 books per person, so: girls are equivalent to 1/20 of the total number of books.
So boys account for (112-1/20) of the total number of books.
Therefore:1÷ (112-1/20) = 30 copies.
The product of three continuous natural numbers is 2 184, so what is their sum?
Solution: 2184 = 2× 2× 3× 7×13 =12×13×14.
Therefore:12+13+14 = 39.
(Generally, prime factors are decomposed first and then analyzed)
( 1 10× 1 10- 1000)× 1/37×0.27÷3
=( 12 100- 1000)× 1/37×0.27÷3
= 1 1 100× 1/37×0.27÷3
=300×0.27÷3
=8 1÷3
=27
There is the simplest score. If the numerator adds 1, the numerator is 2 less than the denominator. If 1 is added to the denominator, the decimal value is equal to 1/2. Find the original score (problem solving process).
Solution: When the numerator adds 1, the numerator is 2 less than the denominator, so the numerator of the original fraction is 2 less than the denominator (2+1).
After the denominator is added with 1, the numerator is smaller than the denominator (2+ 1+ 1) and the fractional value is equal to 1/2, so the numerator is 4 and the denominator is 8.
So the original score was 4/7.