Gita is 12 years older than Harvey.
Let x = Harvey's PRESENT age
Let x + 12 = Gita's PRESENT age

In 4 years, . . . .
x + 4 = Harvey's age IN FOUR YEARS
(x + 12) + 4 = Gita's age IN FOUR YEARS

. . . Gita will be twice as old as Harvey.
So: (Gita's age IN 4 YEARS) = 2(Harvey's age IN 4 YEARS)
In other words: (x + 12) + 4 = 2(x + 4)
Simplify: x + 16 = 2x + 8
Subtract x from both sides: 16 = x + 8
Subtract 8 from both sides: 8 = x

So, Harvey's PRESENT age is 8 years old

How old will Harvey be in 3 years?
Harvey will be 11 years old in 3 years.

Answer: B

Cheers,
Brent

Let present age of Harvey is H and Gita is G

According to the problem Gita's Present age is 12 years more than Harvey's present age so

G = H+12

Again in 4 years Gita's age will be 2wice of Harvey's age then which implies

G+ 4 = 2 * ( H+ 4)

So putting G = H+ 12 above we get
H+16 = 2H + 8

H = 8 and in 3 years Harvey's age will be H+3 = 8+3 =11. Hence B.