Train-RRB

Problem 1

A salesman sold twice as much pears in the afternoon than in the morning. If he sold 360 kilograms of pears that day, how many kilograms did he sell in the morning and how many in the afternoon?
Solution:
Let x be the number of kilograms he sold in the morning.Then in the afternoon he sold 2x kilograms. So, the total is x+2x=3x. This must be equal to 360.
3x=360
x=360/3
x=120
Therefore, the salesman sold 120 kg in the morning and 2⋅120=240 kg in the afternoon.

Problem 2

Mary, Peter, and Lucy were picking chestnuts. Mary picked twice as much chestnuts than Peter. Lucy picked 2 kg more than Peter. Together the three of them picked 26 kg of chestnuts. How many kilograms did each of them pick?
Solution:
Let x be the amount Peter picked. Then Mary and Lucy picked 2x and x+2, respectively. So
x+2x+x+2=26
4x=24
x=6
Therefore, Peter, Mary, and Lucy picked 6, 12, and 8 kg, respectively.

Problem 3

Sophia finished 2/3 of a book. She calculated that she finished 90 more pages than she has yet to read. How long is her book?
Solution:
Let x be the total number of pages in the book, then she finished 2/3⋅x pages.
Then she has x−2/3⋅x=1/3⋅x pages left.
2/3⋅x−1/3⋅x=90
1/3⋅x=90
x=270
So the book is 270 pages long.