A father's age is four times his son's age now. Twenty years from now, the father's age will be double his son's age. What will be the son's age ten years from now?
A Jar contains white, red and green marbles in the ratios 2: 3: 4. Five more green balls are added to the Jar and the ratios become 2: 3: 5. How many white balls are there in the Jar?
Square RSTU shown below is rotated in a plane about its center in a clockwise direction. The minimum number of degrees necessary for T to be in the position where S is
A store usually sells a certain item at 40% profit. One week the store has a sale, during which the item is sold for 10% less than usual price. During the sale, what is the profit percentage the store makes on each of these items?
What is the volume of a cube with a surface area of 96?
A cubical block of metal weighs 6 pounds. How much will another cube of the same metal weigh if its sides are twice as long?