ΔDEF is similar to ΔGHI. Length of DE is 9 cm and length of the corresponding side GH is 16 cm. What is the ratio of areas of Δ DEF : Δ GHI?

The ten's digit of a 2-digit number is greater than the units digit by 7. If we subtract 63 from the number, the new number obtained is a number formed by interchange of the digits. Find the number.

If 2 + 4x < 5 - x/2 and 3x + 3 > -5 - 3x; then x can take which of the following values?

A rice trader buys 16 quintals of rice for Rs 5632. 20% rice is lost in transportation. At what rate should he sell to earn 25% profit?

If (x + y):(x - y) = 11:1, find value of (5x + 3y)/(x - 2y).

The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Rs 8. The sum is ______.

The price of an article is cut by 42%, to restore to its original value, the new price must he increased by ______.

A car travels a certain distance at 70 km/h and comes back at 30 km/h. Find the average speed for total journey.