A rectangular chocolate bar is made of equal squares. Irena breaks off two complete strips of squares and eats the 12 squares she obtains. Later, Jack breaks off one complete strip of squares from the same bar and eats the 9 squares he obtains. How many squares of chocolate are left in the bar?

There are three more square chocolates left

Step-by-step explanation:

We know that Irena breaks off 2 complete strips and eats 12 meaning each strip had 6 squares. Jack breaks off 9. So if we add all the squares into rows of 6, we get four strips of chocolate from the beginning. Since Jack and Irena obtained 21 chocolate squares altogether, we have 3 chocolate squares that are remaining. I hope this helps ;)

1. If it is intersection then it SHOULD be included in both the sets right? Now we know that odd numbers from 1-100 but the second set are multiples of 5 from 50-150! So we mainly need to look for common numbers which are ODD and are a MULTIPLE OF 5 BETWEEN 50 - 100!! So A={51,53,57,59,6199} B={55,60,65,7095} [We stop till 100 because set A has no such element] So what is A ∩ B here? A ∩ B = {All odd numbers and multiples of 5 between 50 - 100}