What are the roots of the quadratic equations?

  $$(x^2 + 3x - 154 = 0)$$

A train passed by a man standing on the platform in 7 seconds and passed by the platform completely in 28 seconds. If the length of the platform is 330 metres, what is the length of the train?

The ratio of the age of a son and father is 1: 4. After 9 years, the ratio will be 2: 5. What is the present age (in years) of the son?

Three partners invested Rs. 42000, Rs. 48000 and Rs. 32000 respectively. partnership condition is that, each will the get interest on his capital at the rate of 7 % p. a. and the remaining profit will be divided in the ratio of their capitals. If at the end of the year the total profit is Rs. 32940, then find the share of A in profit. 

What approximate values should come in place of the question mark(?) in the following question?

The strength of a school increases and decreases in every alternate year by 10 %. It started with increase in 2000, then the strength of the school in 2003 as compared to that in 2000 was : 

The formula is a square of 35 with the multiple method.