Answer:
72 Wrong, so find how many are right with 135 total
Step-by-step explanation:
It's similar to saying if she answered half and this continued how many would she have answered after answering a bigger number, you would say half.
so she answered 8/15 incorrectly a a smaller number, so she will answer that ratio with a bigger number. If it helps 8/15 is about 53%. just like 1/2 is half. So to find half you would multiply something by 1/2 and int he same way you multiply something by 8/15 to get that proportion of it.
so 135, if you take this 53%, or simply multiply it by 8/15 you get your answer of 72. So 72 wrong so al others are right, which you get with 135-72 = 63.
You could also do 135*(1-8/15) = 135 * 7/15. if you ever want to find something NOT part of the proportion you do 1 - that proportion.