The cost of 15 kg of rice is Rs 720 and the cost of 16 kg of wheat is Rs 576. What is the difference between the cost of 45 kg of rice and 56 kg of wheat ?

The average age of 60 boys in a class was calculated as 12 years It was later realised that the actual age of one of the boys in the class was 12.5 years, but it was taken as 14 years. What is the actual average age of the boys in the class ?

Ankit. Puja and Swati begin to jog around a circular stadium. They complete their revolutions in 36 sec, 48 sec and 63 sec respectively. After how many seconds will thev be together at the starting point ?