17. In an equilateral triangle if the midpoints of all the sides are joined then we get four equilateral triangles of equal areas.

    Area of region TWRP = Area of three equilateral triangles = 6.25 ´ 3

    = 18.75

    Ans : D

18. On substituting the appropriate values of m and n, m + n³ bears the least value.

    e.g. consider m = -1 and n = - 2,

    n - 5m = (- 2) - 5 (-1) = - 2 + 5 = 3

    2n - m = 2 (- 2) - (-1) = - 4 + 1 = -3

    n + m = (- 2) + (-1) = - 3

    mn = (-1) ´ (- 2) = 2

    m + n³ = (-1) + (-2)3 = - 1 - 8 = - 9

    Ans : E

19. Draw EF parallel to AB parallel to CD

    

    Ða = (1) + (2)

     

    (1) = 50

    (2) = 35
    a = 50 + 35
    = 85

     

    Ans : A

20. In one hour the machines working together produce 1350 screws.

    \ 1150 screws will be produced in seconds

    i. e. 0.851 or 3067 secs approx.

21. Area of a trapezium = [Sum of parallel sides] ´ distance between them

               = [2x + x] ´ h

               =       ....(I)

    But 2h = 3x

            h =

    substituting h in equation (I), we get

               = .

     

               =

    Ans : B

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Index

Test 3

Test 4