New math problems
- Adam and Ben
When Ben is so many years old to Adam today, Adam will be 23 years old. When Adam was as old as Ben, Ben was two years old. How old is today Ben and Adam?
The trench is a four-sided prism. The cross section has a trapezoidal shape with basements of 4m and 6m, the length of the trench is 30m. What is the depth of the trench if we dig 60,000 l of soil.
- Rhombus sides
find the sides of a rhombus, it area is 550 cm square and altitude is 55cm
- Truncated cone 3
The surface of the truncated rotating cone S = 7697 meters square, the substructure diameter is 56m and 42m, determine the height of the tang.
- Tree shadow 3
A 2-meter rod casts a shadow 3.2 m long. How high is a tree with a shadow of 14.4 m ?
- Two boats
The sightseeing boat sail at 25 km / h. The cruise take 6 hours. How long the another boat sails at 60 km/h?
A pond with two open floodgates will emptied in 20 days. A larger floodgate will emptied whole pond in 30 days. For how long would he be emptied with a smaller floodgate.
The tank is filled with a larger pump in 12 hours and with scond pump in 15 hours. For how long does the tank fill when both pumps are switched on at the same time?
- Water channel
The cross section of the water channel is a trapezoid. The width of the bottom is 19.7 m, the water surface width is 28.5 m, the side walls have a slope of 67°30' and 61°15'. Calculate how much water flows through the channel in 5 minutes if the water flow
- Inner angles
The inner angles of the triangle are 30°, 45° and 105° and its longest side is 10 cm. Calculate the length of the shortest side, write the result in cm up to two decimal places.
- Regular n-gon
In a regular n-angle polygon the internal angle is 144 degrees. Find the number n indicating the number of sides of this polygon.
- Pins 2
how many different possible 4 digits pins can be found on the 10-digit keypad?
Petra has ten pairs of gloves in the closet. Six pairs are blue, 4 pairs are yellow. How many pieces of gloves need to be pulled out at least when she pull them out in the dark and want to have one complete one color pair?
A photocopier enlarges a picture in the ratio 7:4. How many times will a picture of size 6cm by 4cm be enlarged to fit on a 30cm by 20 cm page?
- A map
A map of size 60cm by 25cm is reduced in the ratio of 3:5, twice. What are the new dimensions?
- Bean bag
A student tossed a bean bag. It landed 216 inches away. How many yards are equal to 216 inches?
- Sequence 11
What is the nth term of this sequence 1,1/2,1/3,1/4,1/5 ?
- Arithmetic progression
In some AP applies: 5a2 + 7a5 = 90 s3 = 12 Find the first member a =? and difference d = ?
Cuboid has a surface of 516 cm2. Side a = 6 cm and b = 12 cm. How long is the side c =?
- Surface of cuboid
Find the surface of the cuboid if its volume is 52.8 cm3 and the length of its two edges is 2 cm and 6 cm.