60th to 62nd B.P.S.C. (Pre) 2016
The value of x is a consecutive whole number and the first four value of the expression $x^3 + 3y - 3$ are 7, 20, 45, 88, then the fifth value will be-
a137
b155✓ Correct
c158
d143
eNone of the above/More than one of the above
Explanation
Given that, the expression is $x^3 + 3y - 3$ where the value of x is a whole number or $x = \{0, 1, 2, 3, 4.........\}$ putting x=0 in expression $(0)^3 + 3y - 3 = 7$ $y = \frac{10}{3}$ putting, x=1 in expression $(1)^3 + 3y - 3 = 20$ $y = \frac{22}{3}$ putting, x=2 in expression $(2)^3 + 3y - 3 = 45$ $y = \frac{40}{3}$
general-mental-ability
