Question

In the given pattern, how many white and green triangles will be there in the 4th figure?

• A. Green triangles: 20; White triangles: 18
• B. Green triangles: 15; White triangles: 10
• C. Green triangles: 21; White triangles: 11
• D. Green triangles: 15; White triangles: 10

Answer 1

The correct option is D Green triangles: 15; White triangles: 10

Solution:
Say:
Let us find the pattern rule first to get the answer.
Step:

• Let's count the number of white triangles and the number of green triangles in each figure, and observe the pattern (shown on the white board).
• We can observe that the difference between the number of white triangles in Figure 3 and Figure 2 is one more than the difference between the number of white triangles in Figure 2 and Figure 1 (shown on the white board).
• Following the same process, the number of white triangles in Figure 4 will be 10 (shown on the white board).
• We can observe that the difference between the number of green triangles in Figure 3 and Figure 2 is one more than the difference between the number of green triangles in Figure 2 and Figure 1 (shown on the white board).
• Following the same process, the number of green triangles in Figure 4 will be 15 (shown on the white board).
• Hence option A is correct.

Q. The number of white triangles in any figure is equal to the number of green triangles in the next figure for this pattern. Am I correct?
Ans: No. Instead the number of white triangles in any figure is equal to the number of green triangles in the previous figure.