Explanation:

Let’s break this down step by step:

- Let’s call the total number of persons “T”.

- 18.75% of T live in G, so G = T × 3/16.

- I has 25% more than G ? I = G × 1.25 = T × (3/16) × 1.25 = T × (15/64).

- Total ground floor people: 150.

- G on ground floor: 66?% of G ? (2/3) × G = (2/3) × (3/16)T = (1/8)T.

- I on ground floor: 1/3 × I = (1/3) × (15/64)T = (5/64)T.

- J (ground floor): 30 people.

- Total first floor: 17/32 of T.

- H (first floor): 5 more than G (ground floor), which is (1/8)T + 5.

- H (first floor) is also half of H, so H = 2 × [(1/8)T + 5].

- J (40% first floor): J (first floor) = 0.4 × J.

- Everything adds to T, so T = ground + first = 150 + 17/32 × T.

- Solving: 150 = T - (17/32)T ? 150 = (15/32)T ? T = 320.

Let’s get real numbers now:

- G = 60 (3/16 × 320)

- G (ground): 40 (2/3 × 60)

- I = 75 (1.25 × 60)

- I (ground): 25 (1/3 × 75)

- J (ground): 30

First floor total: 17/32 × 320 = 170.

H (first floor):

- G (ground) = 40, so H (first floor) = 45.

- H = 2 × 45 = 90.

- H (ground) = 90 - 45 = 45.

J: Total = ground + first, J (ground) = 30.

- Let’s call J total = x.

- J (ground) = 30, J (first) = 0.4 × x.

- So 30 + 0.4x = x, x = 50 (Total in J).

- J (first) = 20

K: Total people = T - (G + H + I + J) = 320 - (60 + 90 + 75 + 50) = 45

- All total (ground so far): G(40) + H(45) + I(25) + J(30) = 140, so K (ground) = 150 - 140 = 10

- K (first) = 45 - 10 = 35

Now, let’s sum as question asks:

Total on ground floor in G, H, and I:

G (ground): 40

H (ground): 45

I (ground): 25

Total = 40 + 45 + 25 = 110

Total on first floor in J and K:

J (first): 20

K (first): 35

Total = 20 + 35 = 55

Difference: 110 - 55 = 55

- So, here’s the punchline:

- The correct answer is Option 4: 55.

Recap of the logic in bullet points:

- The math rests on breaking down the percentages and fractions with actual numbers.

- We established the total (T=320), then assigned G, H, I, J, and K populations.

- Used all ground/first floor clues to get each building’s solution.

- Your guess was close, but the right difference is 55, not 45.

So, the correct answer is Option 4: 55.