Which of the following least number can be subtracted from 2486 to make it a perfect square?

Ali travels a distance of 300 m in 2 minutes and 30 seconds. What is his speed in kmph?

When Rahul was born, his father was 32 years older than his brother and his mother was 25 years older than his sister. If Rahul's brother is 6 years older than him and his mother is 3 years younger than his father, how old was Rahul's sister when he was born ?

The ratio of the present ages of Veeru and Sunita is 14:17 respectively. After 6 years from now the ratio of their ages will be 17:20 then, what is the present age of Veeru -

A family consists of a grandmother, father, mother, and their four sons with their respective wives. Further, each son has a daughter and two sons. How many females are there in all?

There were 15 persons in a group, they shook hands with each other, then tell how many times the total number of hands were shaken -

Two years ago, Roshni's age was 3 times her son's age, and 2 years later, 2 times her age would be 5 times her son's age. Find the current age of Roshni.

If “+” denotes ‘ – ‘ , ‘ – ‘ denotes ‘× ‘, ‘×’ denotes ‘÷’  and ‘÷’ denotes ‘+’, then what is the value of
15 – 5 +15 ÷ 45 × 15