Solve the following mathematical problems:

A customer bought 5 pencils and 6 erasers at Tk. 80. Next week the price of each pencil increases by 20% . But the price of eases remains unchanged . Now the customer buys 2 pencils and 3 erasers at Tk. 39. Find the new price of each pencil.

Solve the following mathematical problems:

A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and the speed of the water current respectively?

Solve the following mathematical problems:

3 coins are tossed at random, show the sample space and find the the probability of getting: 

i. One head two tails 

ii. One tail 

iii. One tail and two heads

Solve the following mathematical problems:

A, B and C can complete an work in 12, 15 and 25 days resctively. A and B started working together where area C worked with them in every third day. find the number of days required to complete the work.

Solve the following mathematical problems:

The price of a shirt and a pant together is Tk. 1, 300 . If the price of the shirt increases by 5% and that of the pant by 10% , it costs Tk. 1,405 to buy those two things. Find the respective price of a shirt and a pant.

Solve the following mathematical problems:

Twice the width of a rectangle is 10 meters more the its length. If the area of the region enclosed by the rectangle is 600 square meters , then find its perimeter.