Aptitude Day 64

Problems on Numbers:

 1. 40 is divided into two parts such that the sum of 5 times the first and 20 times the second is 350. The smaller part is:

Solution:

              Let the 2 parts be x and y,

              x+y = 40    ---------- Equation 1

              5x+20y = 350 ------ Equation 2

              By solving equations 1 and 2, we get

              x = 30 and y = 10.

              The smaller part is 10. 

2. The sum of 4 numbers is 81. If 2 is subtracted from the first number, 2 is added to the second number, the third number is divided by 2 and the fourth number is multiplied by 2, then all the results are equal. What’s the largest number?

Solution:

                Let the 4 numbers be A,B,C and D.

                A-2 = B+2 = C/2 = 2D = X

                A= X+2, B = X-2, C = 2X, D = X/2

                X+2+X-2+2X+X/2 = 81

                4X+X/2 = 81

                9X/2 = 81

                X = 18.

                A=20, B= 16, C= 36, D= 9.

               The largest one is 36.