A woman bought eggs at ₹ 30 per dozen, The selling price per hundred so as to gain 12% will be (in ₹)

12 egg cost ₹ 30
Then cost price of 1 eggs = 35 x 12 = #8377; 2.5
Cost price of 100 eggs = 25 x 100 = ₹ 250
Now, let the SP of 100 eggs ₹ N.
Then [(SP - CP) / CP] x 100= profit % [(N - 250)/250] x 100 = 12
⇒ (N - 250)/(2/5) =12
⇒ N- 250 = (12 x 5)/2= 30
N = 250 + 30 = ₹ 280