B is twice as old as A, but half the age of F. C is half the age of A but twice the age of D. Which two persons form the pair of youngest and oldest

Standard deviation of first 7 natural numbers is

Sixty machines can produce 4850 identical mobiles in 5 hours. How many mobiles would 25 machines produce in 6 hours

If a certain sum of money amounts to Rs. 16940 in 6 years at 9%, with simple interest then find the principal amount

Sita and Geetha can to a job in 15 days and 10 days respectively. they began to work together but Sita leaves after some days and Geetha finishes remaining job in 5 days. After how many days did Sita leave

Find the value of √43+√31+√21+√16