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.
Answer & explanation
Correct answer: option 2
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