31.Истакон 250 г об мебарад. Массаи асале, ки ба ин истакон андохта, шудаст чй кадар мебошад? А) 337,5 г; Б) 227,5 г; В) 157,5 г; Д) 207,5 г;

19. The sides of a triangle are in the ratio of \( 2: 3: 4 \). If the perimeter is 72 cm , find its sides. 20. In a factory the ratio of number of defective bolts produced to the number of good bulbs is \( 1: 10 \). In one hour the factory produced 330 bolts. Find the number of defective bulbs produced by the factory in an hour. 21. The present age of father is 45 years and her daughter is 20 years. Find the ratio of (a) present age of father to present age of daughter. (b) age of farther to the age of daughter when daughter was 15 year old. (c) age of daughter to father when father was (c) vears old.

A class of 25 students is making necklaces. The necklaces each have 30 beads. How many beads are needed for each student to make one necklace?

\( 66 \frac{2}{3} \% \) of 60 kg

number of girls is \( 9: 7 \). Find the number of boys if the total number of students is 3200 . 19. The sides of a triangle are in the ratio of \( 2: 3: 4 \). If the perimeter is 72 cm , find its sides. 20. In a factory the ratio of number of defective bolts produced to the number of good bulbs is \( 1: 10 \). In one hour the factory produced 330 bolts. Find the number of defective bulbs produced by the

A car driving in fog passed a man walking at \( 3 \mathrm{~km} / \mathrm{hr} \) in the same direction. He could see the car for 4 minutes and upto a distance of 100 m . What was the speed of the car? \( \begin{array}{llll}\text { 1) } 4.5 \mathrm{~km} / \mathrm{hr} & \text { 2) } 3.5 \mathrm{~km} / \mathrm{hr} & \text { 3) } 5.5 \mathrm{~km} / \mathrm{hr} & \text { 4) } 6 \mathrm{~km} / \mathrm{hr}\end{array} \)