The sum of length, breadth and height of a cuboid is 25 cm. The length of its diagonal is 15 cm. Find the total surface area of the cuboid.

A sum of money amounts to 5,200 in 5 years and to 5,680 in 7 years at simple interest. The rate of interest per annum is-

Akshay has 30 articles, each having the same cost price. He marked the price of each article at 30% above its cost price. He sold 15 of the articles at a discount of 20% each, and the remaining 15 articles at a discount of 10% each, thereby gaining a total profit of ₹630. What was the cost price of each article?

The average marks of a student in four subjects is 75. If the student obtained 80 marks in the 5^th subject then the new average is ?

$$ {\sqrt{784}} × \sqrt{6.25} + 56\%\ of\ 450=?+186$$

The HCF of 156, 312 and 195 is :

Raju, Shobha and Mohan can do a work in 15 days, 20 days and 25 days respectively. In how many days, will the work be finished, if they do it on alternate days?

1 + 2 + 3 + ............. + 49 + 50 + 49 + 48 + ........+ 3 + 2 + 1 is equal to -