If a number is multiplied by 1 / 3 and 2 / 9 respectively, the sum of the two products is 5 / 6?

If a number is multiplied by 1 / 3 and 2 / 9 respectively, the sum of the two products is 5 / 6?

This number = 700 ÷ (3 / 4 + 2 / 9) = 720% d% a% d% A. if you don't understand, please take it. Thank you!

What is the quotient of two products multiplied by 1.5 divided by the opposite number of 9?

The first thing to say is that this kind of mathematical problems, how to look at a little language sickness, but get used to it naturally
The opposite number of 1.5 × 1.5 = 2.259 is - 92.25 ÷ (- 9) = - 0.25

If a four digit product is multiplied by 1,2,3,4,5.19,20, the sum of the numbers in each digit is the same. Please write the four digit product

1188 1485 1980 1998 2475 2970 2997 3960 3996 4950 4995
I programmed it

In all three digits, how many digits are there when the sum of each digit is 19
ditto,

19
=9 + 9 + 1,3 species
=9+8+2
=9+7+3
=9+6+4
=9 + 5 + 5,3 species
=8 + 8 + 3,3 species
=8+7+4
=8+6+5
=7 + 7 + 5,3 species
=7 + 6 + 6,3 species
The other 6 species
There are 3 * 5 + 6 * 5 = 45

How many pairs of numbers from 1 to 100 (1) take any two different numbers and the sum is a multiple of 3? (2) take any two different numbers and multiply them
How many pairs of numbers whose product is a multiple of 3?
It's made of combination
The answer to the first question is 1650, and the answer to the second question is 2739

1. According to the remainder divided by 3, there are 34 remainder 0 and 2, each with 33 remainder 0, any two of which can be: C (33,2) = 33 × 32 △ 2 = 528, each with 1 remainder 1 and 2, or C (34,1) × C (33,1) = 34 × 33 = 1122, a total of 528 + 1122 = 1650

When two positive integers are added together, a two digit number with the same digits is obtained. When the two numbers are multiplied together, a three digit number with the same digits is obtained, and the original two numbers are calculated (the process should be careful)

111 = 3 × 37 (3 + 37 = 40 unsatisfied, rounding off) 222 = 2 × 3 × 37 (3 + 2 × 37 = 77 unsatisfied, 2 × 3 + 37 = 43 unsatisfied, rounding off) 333 = 3 × 3 × 37 (3 × 3 + 37 = 46 unsatisfied, rounding off) 444 = 2 × 2 × 3 × 37 (2 × 3 + 2 × 37 = 80 unsatisfied, rounding off; 2 × 2 × 3 + 37 = 49 unsatisfied, rounding off) 555 = 3 × 5

What is the minimum value of a three digit number whose sum and product of all digits are equal

Let's first set the hundreds as 1, then the other two digits are not 0 (otherwise the sum and product are not equal)
If 10 digits are also 1, then single digit + 2 = single digit, obviously not
If the minimum number of tens can only be 2, then single digit + 3 = single digit × 2, and single digit is 3
The minimum of this three digit number is 123

There is a class of three digit numbers. The sum of the numbers in each digit is 12, and the product of the numbers in each digit is 30. What is the sum of all such three digit numbers?

First, find such a combination of three digits (1,5,6)
So there are 1561655165615651
Sum = 12 * 2 * 111 = 2664

Some three digits, the product of the three digits is 12, so there are () three digits

15

When two natural numbers are added together, the number is two digits; when they are multiplied, the number is three digits, and the three digits are the same. What are the two natural numbers that meet these conditions?

The results are 111, 222, 333, 444, 555, 666, 777, 888 and 999
There are several situations
111 = 3 * 37:3 + 37 = 40, in line with the double-digit
222 = 2 * 3 * 37: 6 + 37 = 43,3 + 74 = 77, in line with the double-digit
333 = 3 * 3 * 37:9 + 37 = 46
444 = 2 * 2 * 3 * 37: 12 + 37 = 49,6 + 74 = 80
555 = 5 * 3 * 37:15 + 37 = 52
666 = 2 * 3 * 3 * 37: 18 + 37 = 55,9 + 74 = 83
777 = 7 * 3 * 37:21 + 37 = 58
888 = 2 * 2 * 2 * 3 * 37: 24 + 37 = 61,12 + 74 = 86
999 = 9 * 3 * 37:27 + 37 = 64
There are 13 possibilities