Correct Answer - Option 3 : 41
Given:
If A gives 3 pens to C, ratio becomes = 19 ∶ 28.
If B gives 2 pens to c, ratio becomes = 7 ∶ 11
The number of pens with B = 37
Calculation:
Let the pens with A, B and C be a, b and c respectively.
If B gives 2 pens to c, ratio becomes = 7 ∶ 11
⇒ (b – 2)/(c + 2) = 7/11
⇒ (37 – 2)/(c + 2) = 7/11
⇒ 385 = 7(c + 2)
⇒ c = 53
Now, If A gives 3 pens to C, ratio becomes = 19 ∶ 28
⇒ (a – 3)/(c + 3) = 19/28
⇒ (a – 3)/(53 + 3) = 19/28
⇒ a = 38 + 3
⇒ a = 41
∴ The number of pens with A is 41.