If sum of ₹ 1664 is divided between P and Q in the ratio of 1/3 : 1/5, then find P's share?

Given that P's share : Q 's share = 1/3 : 1/5 = 5 : 3
Here, a = 5, b = 3, N = 1664
P's share = a/(a + b) x N
∴ = 5/(5 + 3) x 1664 = (5/8) x 1664 = ₹ 1040