WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post UTME Past Questions Agent

An operation (*) is defined on the set T = {-1, 0, ...., 5} by...

Further Mathematics
WAEC 2019

An operation (*) is defined on the set T = {-1, 0, ...., 5} by x * y = x + y - xy. Which of the following operation(s) will give an image that is an element of T?

I. 2(*)5 II. 3(*)2 III. 3(*)4 

  • A. I only
  • B. II only
  • C. I and III only
  • D. II and III only
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Your School's Whatsapp Group - Join Us now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Correct Answer: Option B
Explanation

Given ( x * y = x + y - xy ), and ( T = {-1, 0, 1, 2, 3, 4, 5} ):

I. (2 * 5 = 2 + 5 - 10 = -3 \(\notin T\)) ❌
II. (3 * 2 = 3 + 2 - 6 = -1 \(\in T\) ✅
III. (3 * 4 = 3 + 4 - 12 = -5 \(\notin T\)) ❌

Answer: Only II (3 * 2) gives an element of T.


Report an Error Ask A Question Download App
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post UTME Past Questions Agent
Your School's Whatsapp Group - Join Us now
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post UTME Past Questions Agent
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Your School's Whatsapp Group - Join Us now