A wedding planner uses 72 ivy stems for 18 centerpieces when she arrives at the venue she realizes she will only need 16 centerpieces how many ivy stems should she use so that the ratio of ivy stems to centerpieces stays the same

64 ivy stems

Step-by-step explanation:

To solve this problem we can use rule of three:

Firstly we had 72 ivy stems to use in 18 centerpieces, and know we have 16 centerpieces and want to know how many ivy stems we need to use, so:

18 centerpieces -> 72 ivy stems

16 centerpieces -> X ivy stems

18/16 = 72/X

X = 16*72/18 = 64

He needs to use now 64 ivy stems to maintain the ratio.

34.5 cm

step-by-step explanation:

generally for a circular segment of angle, θ° and radius r

arc length

= (θ/360) x circumference

= (θ/360) x 2πr

in our case, θ = 60°, π=3.142 and r = 33 cm

substitute into above formula

arc length

= (60/360) x 2(3.142)( 33) = 34.5 cm