The speed of a boat when travelling downstream is 32 Kms. / Hr. , whereas when travelling upstream it is 28 kms/hr. What is the speed of the boat in still water ?

4 men can complete a piece of work in 2 days. 4 women can complete the same piece of work in 4 days whereas 5 children can complete the same piece of work in 4 days. If, 2 men, 4 women and 10 children work together, in how many days can the work be completed ?

Three friends J, K and L jog around a circular stadium and complete one round in 12, 18 and 20 seconds respectively. In how many minutes will all the three meet again at the starting point ?

The respective ratio of the present ages of a mother and daughter is 7 : 1. Four years ago the respective ratio of their ages was 19:1. What will be the mother’s age four years from now ?

The compound interest earned by Suresh on a certain amount at the end of two years at the rate of 8 p.c.p.a was Rs. 1,414.4. What was the total amount that Suresh got back at the end of two years in the form of principal plus interest earned?

If '/' means '+ '*'-' means '*' ; ' *' m e a n s ' / ' and '+' means '-'; then

1 5 - 8 * 6 / 1 2 + 4 =?