elementary school skills

Elementary transformations are of the following three types: Interchange of any two rows (or columns) The multiplication of the elements of a row (or column) by a non-zero number. The addition to the elements of any row (or column) the corresponding elements of any other row (or ..

Suppose three students A, B and C measure the volume of the liquid in a cylinder. They report the following values: Result of A: 23.4 mL; Result of B= 23.5 mL; Result of C= 23.6 mL If the correct volume of the liquid is 23.5 mL, it means that the student B has measured the volume of the liquid cor..

In optical microscope, the ray of light can be bent by a lens system. By placing the object and the lens system in such a way, we control the direction of the ray to get a magnified image of the object. Since as 'electron' carriers charge it is possible to change the direction of a electron beam by..

If the electronic compounds like resistors, capacitors, diodes and transistors are compactly put in a small piece of material, it is called as integrated circuit. This single small package performs a complete electronic function. Thin slice of crystal of silicon of the order of 0.5 cm, are cal..

A teacher wants 5 of her 15 students to write a skill test. In how many ways can she select 5 students? => 3008 or 2998 or 3013 or 3003..

The enrollments made in elementary schools and high schools from 1994 through 1998 is shown in the double bar graph. Which year has the maximum difference between enrollments of high schools and elementary schools? => 1994 or 1997 or 1995 ..

25 children from Ever Dale Elementary School are going on a picnic in vans. Each van can hold 7 children and the driver. How many vans must be rented? => 5 or 6 or 4 or 3..

A random sample of 81 students was tested for the problem solving approach skills. The variance of the scores obtained from the sample was found to be 144. Find the 80% confidence interval for the variance and standard deviation. Assume that the variable is normally distributed. => 122 &l..

289 elementary school students and 120 middle school students wrote letters for a time capsule. Estimate the total number of letters written. => 410 or 400 or 300 or 500..

At a fair, a boy tries his skill in shooting. He was to receive $2 for hitting the bull's eye and had to pay $0.50 for missing the bull's eye. He tried 30 shots, but received only $32.50. How many times did he hit the bull's eye? => 21 or 19 or 62.50 or 15..