A story book has 40 pages, accounting for two-thirds of the whole book. How many pages is the book? What is the number of pages? Let's say that the book consists of X pages and the equation is?

A story book has 40 pages, accounting for two-thirds of the whole book. How many pages is the book? What is the number of pages? Let's say that the book consists of X pages and the equation is?

Two thirds x = 40

Find the rules and fill in the numbers 1,4,9,25, (), (), (), ()
Fifth grade math problems

The law of this problem is the square of prime numbers, because prime numbers are 1, 2, 3, 5, 7, 11, 13, 17 So this problem is the square of 1, the square of 2, the square of 3, the square of 5, the square of 7, the square of 11, the square of 13, the square of 17 Therefore, the title is 1,4,9,25, (49), (121), (169), (289)

1 / 2, 1 / 3, 1 / 10, 1 / 15, 1 / 26, 1 / 35 according to this rule, what is the next number

Look at the denominator
3-2=1
10-3=7
15-10=5
26-15=11
35-26=9
1,5,9 are arithmetic sequences with tolerance 4
7 and 11 are arithmetic sequences with tolerance of 4
So the next one is 11 + 4 = 15
So the denominator is 35 + 15 = 50, that is 1 / 50

1 / 2, 1 / 3, 1 / 10, 1 / 15, 1 / 26, 1 / 35
1 / 2 = half,

The denominators are as follows:
1^2+1=2
2^2-1=3
3^2+1=10
4^2-1=15
5^2+1=26
6^2-1=35
7^2+1=50
So the seventh number is 1 / 50