The ratio of present ages of Suresh and Manish are 5 : 1 respectively. After how many years the ratio of the ages of Suresh and Manish will become 3 : 1 if the present age of Manish is 7 years -

If all the faces of a big cube are painted red and it is cut into 64 identical smaller cubes, then the number of colored cubes on two adjacent faces is -

The pages of a book had been numbered 1 to 100 manually. How many times will it be essential to write the digit 5? 

If A, represent ‘ – ‘ and C, represent ‘ × ‘, D represent ‘÷’, and E represent ‘+’ then the value of
14 C 3 A 12 E 4 D 2=?

If 879=8, 625=1, 586=9, then 785=?

In a family, each daughter has the same number of brothers as she has sisters and each son has twice as many sister as he has brothers. How many sons are there in the family?

Reena is twice as old as Sunita. Three years ago, she was three time as old as Sunita. How old is Reena now?

Which two signs should be interchanged to make the following equation correct?
5 + 3 x 8 - 12 ÷ 4 = 3