Riordan and Ben have some yellow pencils and some blue pencils. The number of blue pencils Riordan has is equal to the number of yellow pencils Ben has. ¹₄ of Riordan's pencils are yellow and ¹₆ of Ben's pencils are blue. There are a total of 140 yellow pencils. Find the total number of pencils they have.

Riordan		Ben		Total
Yellow	Blue	Yellow	Blue
	1x15	1x15
1x5	3x5	5x3	1x3
5 u	15 u	15 u	3 u	38 u

The number of Riordan's blue pencils and Ben's yellow pencils is the same.

The number of Riordan's blue pencils is repeated. The number of Ben's yellow pencils is repeated.  Make the number of Riordan's blue pencils and Ben's yellow pencils the same.  LCM of 3 and 4 is 15.

Number of yellow pencils
= 5 u + 15 u
= 20 u

20 u = 140

1 u = 140 ÷ 20 = 7

Total number of pencils
= 5 u + 15 u + 15 u + 3 u
= 38 u
= 38 x 7
= 266

Answer(s): 266