Solution -:
1.(4) Pranab × 25/100 = Surya × 80/100
= Pranab/ Surya = 80/25 = 16/5
Pranab : Surya = 16: 5
Surya/ Dheeru = 40/100 = 2/5
Surya : Dheera = 2 : 5
Pranab : Surya : Dheeru
= 16 × 2 : 5 × 2 : 5 × 5
= 32 : 10 : 25
Now,
∴ 25 =600000
∴ 32 = 600000/25 × 32
= Rs. 768000 = Pranab’ annual income
∴ Pranab’s monthly salary
= 768000/12 = Rs. 64000
2.(3) Sum of the angles of quadrilateral = 360˚
= x + 6x + 2x + 45 = 360
= 9x = 360 – 45 = 315
= x = 315/9 = 35
3.(3) Sum of the angles of a quadrilateral = 360˚
∴ 3x + 4x + 6x +5x = 360˚
= 18x = 360˚
x = 20˚
∴ The largest angle of the quadrilateral = 6 × 20 = 120˚
∴ Smaller angel of parallelogram
= 120 × 2/3 = 80˚
∴ Its adjacent angle
= 180 – 80 = 100˚
4.(3) If the number of 2 rupee coins be x, then number
of 5 rupee cons = x- 5
∴ 2x + 5 (x – 5) = 50 – 26
= 2x + 5x – 25 = 24
= 7x = 24 + 25 = 49
x = 49/7 = 7
5.(5) Let the adjacent angles of parallelogram be 2x˚
and 3x˚ respectively, then
2x˚ + 3x˚ = 180˚
= 5x˚ = 180˚ = x˚ = 36˚
∴ Smallest angle of parallelogram
= 2x = 72˚
= smallest angle of the quadrilateral = 36˚
∴ Its largest angle = 4 × 36 = 144˚
∴ Required sum = 144 + 72 = 216˚
6.(3) Sum of adjacent angles of a parallelogram = 180˚
∴ One of the angles of triangle
= 2/3 × 180˚ = 120˚
Sum of three angles of a triangle
= 180˚ ∴ 5x + 7x = 180 – 120
= 12x = 60
x = 5
Second angle of triangle
= 5 × 5 = 25˚
Third angle of triangle
= 7 × 5 = 35˚
∴ The second largest angle of triangle
= 35˚
7.(3) Sum of angles of a triangle = 180˚
= 3x + x + 44 = 180
= 4x = 180 – 44 = 136
x = 136/4 = 34
∴ Largest angle of triangle
= 3 × 34 = 102˚
∴ 150% of 102 = 102 × 150/100 = 153
8.(2) For the Parallelogram,
4x˚ + 5x˚ = 180˚
= 9x = 180
x = 180/9 = 20
Smaller angle of parallelogram
= 4 × 20 = 80˚
∴ One angle of quadrilateral
= 3 × 80 = 240˚
Now, 4y + 11y + 9y
= 360 – 240 = 120
= 24 y = 120
= y = 120/24 = 5
= Its smallest angle
= 4 × 5 = 20˚
∴ Required sum
= 240˚ + 20˚ = 260˚
9.(2) Sum of the angles of quadrilateral = 360˚
∴ 3x + 4x + 5x + 6x = 360
= 18x = 360
x = 360/18 = 20
∴ Smallest angle of quadrilateral =
3 × 20 = 60˚
Largest angle of quadrilateral
= 6 × 20 = 120˚
∴ smallest angle of triangle
= 60 × 2/3 = 40˚
Largest angle of triangle
= 2 × 40 = 80˚
∴ Third angle of triangle
= 180˚ – 40˚ – 80˚ = 60˚
∴ Required sum
= 60 + 120 = 180˚
10.(3) The smallest angle of triangle is half of the largest
angle.
∴ Ratio of three angles = 4 : 3 : 2
Now, 4x + 3x + 2x = 180
= 9x = 180
= x = 20
∴ Required difference
= 4x + 3x + 2x = 180
= 9x = 180
x= 20
∴ Required difference
= 4x – 2x = 2x
