Given the functions f(x) = 3x + 1 and g(x) = x3 - 1, what is the result of 3f(g(3))?

Given the functions f(x) = 3x + 1 and g(x) =… | GMAT Sprint

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PS · Problem Solving

sub-505

Functions

Given the functions $f(x) = 3x + 1$ and $g(x) = \frac{x}{3} - 1$ , what is the result of $3f(g(3))$ ?

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Official Explanation

Official

Let's break this down step by step: we have f(x) = 3x + 1 and g(x) = (x/3) - 1. We need to find: 3f(g(3)). First, we calculate g(3) by substituting x with 3 in g(x) =…

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Comments

ClelioFeb 11, 2025

this pattern comes up frequently

AmanDec 3, 2024

Great!

SomaliSep 22

thanks, this was a nice quick one

AbhijeetJun 10

easy but i almost forgot the 3 sitting outside the f at the end. classic trap

RewantAug 5

huh i got 12 because i multiplied wrong somewhere. anyone else land on an answer choice that wasnt right?

PhilippAug 12

check if you used g(3) or 3g(3)

What this question tests

What it tests

Your ability to evaluate and compose functions, including unusual defined operations.

Common trap

Applying function operations in the wrong order or ignoring domain restrictions.

Given the functions f(x)=3x+1f(x) = 3x + 1f(x)=3x+1 and g(x)=x3−1g(x) = \frac{x}{3} - 1g(x)=3x​−1, what is the result of 3f(g(3))3f(g(3))3f(g(3))?