Product of digits of a 2-digit number is 15. If we add 18 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.
Assuming that the numbers in each of the following figures follow a similar pattern, select the option that can replace the question mark (?) in figure C.
D and E are points on the sides AB and AC respectively of ΔABC such that DE is parallel to BC and AD:DB = 4:5, CD and BE intersect each other at F. Then the ratio of the areas of ΔDEF and ΔCBF