Quantitative Reasoning – Pyramid of Numbers!

2014_QNR 21. Neha has blocks with numbers printed on it. She makes a pyramid so that the sum of the two adjacent blocks is equal to the number on the block placed above them (as shown below).2014_QNR 21_0 If she applies the same principle to make a pyramid of 15 blocks as shown below, what number must replace the question mark (?) ?
2014_QNR 21_1

(1) 72

(2) 58

(3) 59

(4) 60

Ans: Let us start working from the lower blocks and up higher. We should be able to get the below figure after filling in the lower blank blocks:

2014_QNR 21_2

[‘A’ is an assumption on the middlemost lower block as we don’t know what value might fit in]. From the figure we can conclude that (17+A) + (A+1) = 42 => 2A = 24. A= 12

From here, we should be able to get the below figure:

2014_QNR 21_2

Hence, answer option (4).

Leave a Reply

Your email address will not be published. Required fields are marked *