Find the HCF of the numbers 18, 24 and 30 by factor tree method.

There are four Mobile Phones in a house. At 5 a.m, all the four Mobile Phones will ring together. Thereafter, the first one rings every 15 minutes, the second one rings every 20 minutes, the third one rings every 25 minutes and the fourth one rings every 30 minutes. At what time, will the four Mobile Phones ring together again?

Find the duration between 6 a.m and 4 p.m

The clock is set at 7 a.m. If the clock slows down two minutes every hour, find the time shown by the clock at 6 p.m.

Prepare a bill for the following purchases at Aavin sales counter in Coimbatore on 25-06-2018 bearing the Bill number 160.
1. 5 packets Milk Khoa of 100 gm @ Rs. 40 each
2. 5 packets of Butter Milk @ Rs. 8 each
3. 6 packets Milk of 500ml @ Rs. 25 each
4. 5 packets Ghee of 100gm @ Rs. 40 each

Wheat is being sold at Rs. 1550 per bag of 25 kg at a profit of Rs. 150. Find the cost price of the wheat bag.

Can a triangle be formed with the following sides? If yes, name the type of triangle.
(i) 8 cm, 6 cm, 4 cm
(ii) 10 cm, 8 cm, 5 cm
(iii) 6.2 cm, 1.3 cm, 3.5 cm
(iv) 6 cm, 6 cm, 4 cm
(v) 3.5 cm, 3.5 cm, 3.5 cm
(vi) 9 cm, 4 cm, 5 cm

Two angles of the triangles are given. Find the third angle.
(i) 80°, 60° 
(ii) 75°, 35°
(iii) 52°, 68°
(iv) 50°, 90°
(v) 120°, 30° 
(vi) 55°, 85°

Construct a line perpendicular to the given line at a point on the line.

Draw a line segment AB = 6.5 cm and mark a point M above it. Through M draw a line parallel to AB.

Draw a line segment PQ = 12 cm. Mark two points M, N at a distance of 5 cm above the line segment PQ. Through M and N draw a line parallel to PQ.

Two sides of the triangle are given in the table. Find the third side of the triangle.

Sl. No.	Side – 1	Side - 2	The length of the third side(any three measures)
i.	7 cm	4 cm
ii.	8 cm	8 cm
iii.	7.5 cm	3.5 cm
iv.	10 cm	14 cm

Convert the following algebraic expressions into tree diagrams.
(i) 10v
(ii) 3a−b
(iii) 5x + y
(iv) 20t \(\times\) p
(v) 2(a+b)
(vi) (x \(\times\) y) − (y \(\times\) z)
(vii) 4 x + 5y
(viii) (lm − n) \(\div \) (pq + r)

Convert the following questions into tree diagrams:
(i) The number of people who visited a library in the last 5 months were 1210, 2100, 2550, 3160 and 3310. Draw the tree diagram of the total number of people who had used the library for the 5 months.
(ii) Ram had a bank deposit of Rs. 7,55,250 and he had withdrawn Rs. 5,34,500 for educational purpose. Find the amount left in his account. Draw a tree diagram for this.
(iii) In a cycle factory, 1,600 bicycles were manufactured on a day. Draw tree diagram to find the number of bicycles produced in 20 days.
(iv) A company with 30 employees decided to distribute Rs. 90,000 as a special bonus equally among its employees. Draw tree diagram to show how much will each receive?

Use brackets in appropriate place to the expression 3 \(\times\) 8 − 5 which gives 19 and convert it into tree diagram for it.