Direction : What value should come in the place of question mark (?) in the following questions?

$$ \sqrt{576}+\sqrt{841} =(?) $$

Direction : What value should come in the place of question mark (?) in the following questions?

$${210\over14}×{17\over15}×?=4096  $$

Direction : What value should come in the place of question mark (?) in the following questions?

23 × 45 ÷ 15=?

Direction : What value should come in the place of question mark (?) in the following questions?

3.6 + 36.6 +3.66+0.36+3.0=?

A starts some business with ₹ 50,000. After 3 months B joins him with ₹ 70,000. At the end of the year, in what ratio should they share the profit? 

Mohan, a shopkeeper, bought a shirt of list price ₹225 at a discount of 20%. If he wants a profit of 30% then he should sell the shirt for:

Cost of 36 pens and 42 Pencils is Rs 460. What is the cost of 18 pens and 21 pencils?

If the graph of the equations x + y = 0 and 5y + 7x =24 intersect at (m, n), then the value of m + n is :