How much of 200 Rs / kg type tea should be mixed with 12 kg of 100 Rs / kg type tea to make 160 Rs / kg of branded tea ?

(16)²- 5³ + √169 = (?)²

(6)² + (8)² + (2)² - (9)²=?

5434+5782=? * 25 

4561 + 3254 =5422 +?

0.01 X 0.1 - 0.001 ÷10 + 0.01 = ?

(98x198)÷(48x148)=?

(0.04)? x (0.2)? ÷ (0.008)^2 =(0.2)?

13 16 21 27 39 52 69

Three pencils , four erasers and two sharpeners together cost Rs. 10.50. Two pencils one eraser and three sharpeners together cost Rs. 9.50. How much does each eraser cost?