**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*