At simple interest of 5%, 6% and 8% for three consecutive years, the interest earned is ₹ 760. find the principle.?

Let the principle be ₹ P .
Then,
(P x 1 x 5)/100 + (P x 1 x 6)/100 + (P x 1 x 8)/100 = 760
⇒ 5P/100 + 6P/100 + 8P/100 = 760
⇒ 19P = 760 x 100
∴ P = (760 x 100)/19 = ₹ 4000
Hence, the principle is ₹ 4000.