SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Write the given data
![\begin{gathered} n=10 \\ r=7 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mpgha18o0tg41y0mz9ts6uezcyk0dm8eo3.png)
STEP 2: answer question a
![^nC_r=(n!)/((n-r)!r!)](https://img.qammunity.org/2023/formulas/mathematics/college/1q6cebegtgha4ctlij3deo1h0foedhbfzo.png)
To get the answer,
![\begin{gathered} ^(10)C_7=(10!)/((10-7)!7!) \\ =(10*9*8*7!)/(3!7!)=(10*9*8)/(3!)=120 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zrdjw7qvkkgpouhg7pgqo53mm2yskaobld.png)
Hence, 120 different toppings pizza are possible
STEP 3: Answer question b
![=^(75)C_4=(75!)/((75-4)!4!)=1215450](https://img.qammunity.org/2023/formulas/mathematics/college/zdkobb15s7mp1fo6uw1hui6mg822vv25gu.png)
Hence, 1215450 mini-boxes are possible