rahul.s wrote:A jeweler ships a package of N necklaces and R rings to a client. The jeweler must pay $4 to insure each necklace and $2 to insure each ring. If the jeweler ships 55 pieces of jewelery, what is R?

(1) 20 < N < 30
(2) The jeweler pays less than $153 to insure the entire package

OA: C
Source: Knewton

how do we solve statement 2. could someone simplify it for me?

N+R = 55

1) 20 <N<30

2) 4N + 2R <153

Minimum value of N is 21, Insufficient

Combining
If N = 21

21*4 + 2R <153
R< 34.5

If N =21 there is only one solution R=34 since N+R =55

Now if N =22
22*4 + 2R <153
R<32.5

no solution The max is when R=32 and N= 22 but N+R is not 55 in that case

Thus we can see as N increases there is no solution for R

the only solution is N=21 and R = 34