Bodhee Prep-Online CAT Coaching | Online CAT Preparation | CAT Online Courses

Get 10% OFF on CAT 24 Course. Code: BODHEE10. valid till 3rd Dec Enroll Now

CAT 2020 Quant Question [Slot 3] with Solution 08

Question

If \(f(x + y) = f(x)f(y)\) and \(f(5) = 4,\) then \(f(10) - f( - 10)\) is equal to

  1. 0
  2. 15.9375
  3. 3
  4. 14.0625
Option: 2
Solution:

Given \(f(x + y) = f(x)f(y)\)

\( \Rightarrow f(x) = {a^x}\)( where \(a\) is a constant ) Given, \(f(5) = 4 \Rightarrow {a^5} = 4 \Rightarrow a = {2^{2/5}}\)

\(f(10) - f( - 10) = {a^{10}} - {a^{ - 10}} = {\left( {{2^{\frac{2}{5}}}} \right)^{10}} - {\left( {{2^{\frac{2}{5}}}} \right)^{ - 10}}\)

\( = {2^4} - {2^{ - 4}} = 16 - \frac{1}{{16}} = 15.9375\)

CAT Online Course @ INR 12999 only

CAT 2020 Quant questions with Solutions

CAT online Courses

CAT 2023 Mock Test Series

  • 400+ Topic Tests
  • 45 Sectional tests
  • 20 Mock Tests (Video Solutions)
  • Only at INR 2499

20% Discount Code: GET20

FREE CAT Prep Whatsapp Group

CAT 2023 Online Course at affordable price