Answer:
150 situps
Step-by-step explanation:
I think the best way to solve these types of problems in conceptually. If Gianna has only done 20% of her goal, we can ask ourselves by what number can we multiply 20% by to get 100%. In this case it is 5.
This equation looks like 5 x 20% = 100%
So, now that we know a factor of 5 will get us to Gianna's total goal, we just need to multiply the 30 situps she has already done by 5 and we will get 150 situps.
This could also be solved by setting up a conversion. which would look like:
30 situps/ 20% = ? number of situps/ 100%
Now solve for the ? number of situps. You can treat the percentages as regular whole numbers.
Either way will give you the answer of 150 situps.
hope this helps! :)