Equalising Units Concept (Identical Side)

A pen costs 4 times as much as a book.
A file costs 1/4 as much as the book.
If 2 such files and a book cost $18, find the cost of a pen.

(Find the smallest item and make it 1u)
File = 1u
Book = 4u
Pen = 4 × 4 = 16u

2 files + 1 book = 2u + 4u = 6u
6u = $18
Pen = 16u = 18 ÷ 6 × 16 = 48

Ratio Method:
File : Book
= 1 : 4

Pen : Book
= 4 : 1
= 16 : 4

2 Files + 1 Book = 6u
Pen = 48

There are three types of cookies in a box.
The ratio of the number of walnut cookies to chocolate cookies is 4:5.
The ratio of the number of raisin cookies to the total number of walnut and chocolate cookies is 5:6.
What fraction of the fookies in the box are chocolate cookies?

Devi and Teela were given some beads. While making necklaces, if Devi uses four times as many beads as Teela, Teela will still have 932 beads when Devi has used all her beads. If Devi uses half as many beads as Teela, Teela will still have 221 beads when Devi has used all her beads. 

(a) How many more beads did Teela has? 

(b) Altogether how many beads have they been given? 

(Case 1)

Devi : Teela

= 4 : 1

(Case 2)

Devi : Teela

= 1 : 2

= 4 : 8

(Teela)

1u + 932 = 8u + 221

7u = 932 - 221 = 711

Error in Data