Answer:
(a)90
(b)(i) 10 (ii)6 (iii)5
Step-by-step explanation:
Part A
First, we find the lowest common multiple of 9,15, and 18.
To do this, express each number as a product of its prime factors.
![\begin{gathered} 9=3*3 \\ 15=3*5 \\ 18=2*3*3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/9ygboobje7qznptoff42ntefqy7hyiopr2.png)
Next, multiply all prime factors the greatest number of times they occur in either number.
![\text{LCM}=2*3*3*5=90](https://img.qammunity.org/2023/formulas/mathematics/high-school/si5941rv81czc8b8z07hvoypi46eavuc47.png)
The LCM of 9, 15, and 18 is 90.
Part B
To answer this part, divide the LCM by the respective numbers:
(i)
![(90)/(9)=10](https://img.qammunity.org/2023/formulas/mathematics/college/434jhszb9ov586msx26y1dfj9qhhqdunut.png)
9 divides into LCM 10 times.
(ii)
![(90)/(15)=6](https://img.qammunity.org/2023/formulas/mathematics/high-school/wc06sfnd4gk4fhymxjxbz27x2igb4v0cju.png)
15 divides into LCM 6 times.
(iii)
![(90)/(18)=5](https://img.qammunity.org/2023/formulas/mathematics/high-school/8oo06j669gtidpd46euvaisofx7lpqbo6z.png)
18 divides into LCM 5 times.