MHB Struggling to solve number pattern question Please help

  • Thread starter Thread starter yiannicart
  • Start date Start date
AI Thread Summary
The discussion revolves around a number pattern question involving three sets of numbers. The user, Yianni, seeks help in understanding how to derive the missing number in the sequence. The correct answer is identified as 33, with the rule being that the third number is half the difference between the first and second numbers. This pattern is confirmed through calculations for each set. Yianni expresses gratitude for the clarification provided.
yiannicart
Messages
2
Reaction score
0
Hi,
I am in my final year of Secondary Teaching, specialising in history and language, so mathematics isn't always my strong point.:p
I tutor middle school students for extra money, and am helping one through a number reasoning test.

The question is as follows:

The numbers in each of the three brackets follow the same rule. Find the missing number.
[19, 25, 3] [4, 26, 11] [?, 51, 9]

A. 20
B. 31
C. 33 (the correct answer)
D. 34I cannot seem to find how 33 is the correct answer (I only know via the answer book), let alone the rule/pattern the numbers are following. If anyone can explain this to me and shed some light on this, it would be extremely helpful for me and for my student.
Cheers,
Yianni :D
 
Mathematics news on Phys.org
Hi yiannicart and welcome to MHB! :D

It appears that the third number is half the difference between the first and second numbers:

(25 - 19)/2 = 3, (26 - 4)/2 = 11, (51 - 33)/2 = 9.
 
greg1313 said:
Hi yiannicart and welcome to MHB! :D

It appears that the third number is half the difference between the first and second numbers:

(25 - 19)/2 = 3, (26 - 4)/2 = 11, (51 - 33)/2 = 9.
Hi greg1313,
Thank you so much! This helps so much!
Kindest regards from Australia!
Yianni
 
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
Back
Top