Explanation:

Let’s break this down step by step:

- There are 60 students in the class.

- Boys are 5/7 times the number of girls.

- Let’s call the number of girls G and boys B.

- B = (5/7) × G

- G + B = 60 ? G + (5/7)G = 60 ? (12/7)G = 60 ? G = 35

- So, number of girls = 35, boys = 25.

- Ratio of girls who like Rose to total girls is 2:7.

- Girls liking Rose = (2/7) × 35 = 10

- Boys who like Sunflower = 60% of girls who like Rose.

- 60% of 10 = 6

- Girls who like Sunflower = 2.5 × boys who like Sunflower

- 2.5 × 6 = 15 girls like Sunflower

- Girls who like Sunflower = 150% of boys who like Lotus

- 15 = 1.5 × X ? X (boys who like Lotus) = 10

Now let’s check options:

1. 30 (No, we got 35)

2. 25 (No)

3. 35 (Yes, matches calculation) 

4. 40 (No)

5. None of these (No)

So the total number of girls is 35. Correct Option: 3.