The ratio of present ages of Shyam and Sohan is 7: 8 respectively. Four year hence this ratio becomes 9: 10 respectively. What is Shyam's present age in years?

$$ \sqrt {sec^2{θ}+cosec^2{θ}}=?$$

If 2sin² θ – 3 sin θ + 1 = 0,   θ being positive angle, then the values of θ are : 

The total cost of 18 pens and 23 pencils is Rs. 231, while the total cost of 7 pens and 13 pencils is Rs. 102. What is the cost of 4 pens and 9 pencils?

The simple interest for four years is one fourth of the principal. At the same rate, which amount become Rs.450 total amount in 2 years?

What is the value of a⁵ × a⁷ ?

A train 150 m. long is running with a speed of 68 km. /hr. In what time will it pass a man who is running at 8 km. /hr. in the same direction in which the train is going?

The heights of Arun’s family members are given in cm’s as 165, 180, 181, 163, 172, 180, 162 The median height of the family will be