DECIMAL FRACTIONS - EXERCISE 3 (SOLUTION 31 TO 40)

31.  2 x 5 = 10. Sum of decimal places = 4.

                    0.002 x 0.5 = 0.00010 = 0.001.

32.  1602 x 1 = 1602. Sum of decimal places = 5.

               16.02 x 0.5 = 0.0010 = 0.001.

33.  14 x 14 = 196. Sum of decimal places = 6.

                            0.0014 x 0.001 = 0.000196.

34.  4083 x 102 x 12 = 4997592. Sum o decimal places = 5.

                         40.83 x 1.02 x 1.2 = 49.97592.

35.  4 x 162 = 648. Sum of decimal places = 6.

                          0.04 x 0.0162 ==.000648 = 6.48 x 10⁻⁴

36.   3 x 3 x 3 x 3 x 30= 2430. Sum of decimal places = 6.

                      3 x 0.3 x 0.03 x 0.003 x 30 = 0.002430 = 0.00243.

37.  Sum of decimal places = 7.

                        Since the last digit to the extreme right will be zero (5 x 4 = 20), so there will be                                          6                 significant digits to the right of the decimal point.

38.   (.00625 of 23/6) = (625/100000 x 23/5) = 23/800.

39.  Given product = 0.3 x 0.25 x 0.5 x 0.125 x 24

                    = (3.10 x 25/100 x 5/10 x 125/1000 x 24) = 9/80 = 1/8

DECIMAL FRACTIONS - EXERCISE 3 (SOLUTION 21 TO 30)

21.  Given expression = (12.1212 + 17.0005) -9.1102 = (29.1217 – 9.1102) = 20.0115.

22.  Given expression = 892.7 – (573.07 +95.007) =892.7 – 668.077 = 224. 623.

23.  Let 3889 + 12.952 – X = 3854.002.

                   Then X = (3889 + 12.952) – 3854.002 = 3901.952 – 3854. 002 = 47.95.

24.    Let 138.009 + 341. 981 ) – 146.305=123.6 + X.

                     Then, X = (138.009 + 341.981) – (146.305 + 123.6)= 479.99 – 269.905 = 210.085.

25.  Let 832.58 – 242.31 = 779.84 –X .

                      Then, X = (779.84 + 242.31) – 832.58 = 1022.15 – 832.58 = 189.57.

26.  Let X + 542 + 5.43 = 603.26. then, X = 603.26 – (543 + 5.43 ) =603.26 – 548.43 = 54.83.

                         Missing digit = 8.

27.  3.14 x 10⁶ = 3.140000 x 1000000 = 3140000.

28.  518.000,000 = 5.18 x 100000000 = 5.18 x 10⁸.

29.  0.000006723 = 0.000006723 x 10⁶/10⁶ = 6.723 x 10⁻⁶.

30.  10 k = 0.001125/1.125 = 1.125/1125 = 1.125 x 10³/1125 x 10³ = 1/10³ = 10⁻³.

                      K=-3.

Aptitude Questions and Answers

Time and Work, Boats and Streams,  Pipes and Cistern, Surds and Indices, Chain Rule, Square Root and Cube Root, Problems on H.C.F and L.C.M, Decimal Fraction, Problems on Numbers, Permutation and Combination,