There are 5 numbers, where first number is double of second number and two-third of third number. The average of 5 numbers is 60. If the sum of remaining two numbers is 120, then find the value of the 3rd number.

90

Lets assume 5 numbers be a, b, c, d, e

⇒ a + b + c + d + e = 5 x 60 = 300

Given, a = 2b

          b = \(\frac{a}{2}\)

          a = \(\frac{2c}{3}\)

          c = \(\frac{3a}{2}\)

Sum of remaining 2 numbers = 120

⇒ d + e = 120

Putting values of b, c, d and e

⇒ a + b + c + d + e = 300

⇒ a + \(\frac{a}{2}\) + \(\frac{3a}{2}\) + 120 = 300

⇒ \(\frac{6a}{2}\) = 180

⇒ a = 60

Value of 3rd number = 90