Combination

mgmt_gmat wrote:53) 2 sizes of sticky pads. Each has 4 colors – Blue, Green, Yellow, and Purple. The pads are packed in packages that contain either 3 notepads of same size and same color or 3 notepads of same size and of 3 different colors. How many different packages of the types described are possible?
a. 6
b. 8
c. 16
d. 24
e. 32

OA later

IMO C

3 notepads of same size and same color =2C1*4C1=8
or 3 notepads of same size and of 3 different colors=2C1*4C3=8

tot=16

mgmt_gmat wrote:53) 2 sizes of sticky pads. Each has 4 colors – Blue, Green, Yellow, and Purple. The pads are packed in packages that contain either 3 notepads of same size and same color or 3 notepads of same size and of 3 different colors. How many different packages of the types described are possible?
a. 6
b. 8
c. 16
d. 24
e. 32

OA later

This question requires the concept that we have to check for event twice, 1st against size and second against color

Now for selecting a single size out of two we have = 2 ways
For selecting same color we have = 4 ways (any of green blue yellow purple)
so total ways of selecting 3 notepads of same color and and same size = 4x2 = 8 ways

Again for selecting a single size out of two we have = 2 ways
For selecting different color we have = 4ways (gby,bpy,byp,gbp)
so total ways of selecting 3 notepads of different color and and same size = 4x2 = 8 ways

so total no. of ways = 16 [spoiler]Ans C
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Dear all,

Please don't entertain such redundant posts. The question is already discussed several times. Here are a few,

https://www.beatthegmat.com/sticky-pads-t47448.html
https://www.beatthegmat.com/sticky-pads-t40828.html

Please maintain this forum clean!