Answer:
31
Step-by-step explanation:
To solve this problem, we must find the lowest common multiple of 21, 35 and 63
Find the prime factors of the number;
Prime factors of 21 = 3 x 7
35 = 3 x 5
63 = 3 x 3 x 7
The lcm = 3 x 3 x 5 x 7 = 315
The numbers between 1 and 10, 000 divided by these three numbers;
First number = 315
Last number = 9765
Now the total number:
= [tex]\frac{first number - last number }{315} + 1[/tex]
= [tex]\frac{9765 - 315}{315}[/tex] + 1
= 30 + 1
= 31
