The cost of 3 chocolates, 5 biscuits, and 5 ice creams is 195. What is

Let chocolate, biscuits, and ice cream be c, b, r, respectively.

Known: 3c + 5b + 5r = 195.

Q. 7c + 11b + 9r = ?

(1) 5c + 7b + 3r = 217.
--> 3*(3c + 5b + 5r) + (5c + 7b + 3r) = 3*195 + 217
14c + 22b + 18r = 802
7c + 11b + 9r = 401
SUFFICIENT

(2) 4c + b + 3r = 141.
--> (3c + 5b + 5r) + (4c + b + 3r)
7c + 6b + 8r, but we are no closer to 7c + 11b + 9r. Thus, we need one more equation to solve c, b, and r.
NOT SUFFICIENT

FINAL ANSWER IS (A)

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The question has 3 unknowns and potentially 2 equations (A,B) or we have a choice of 3 unknowns and 3 equations (C). So it is tempting to choose C. But the question does not ask to evaluate all 3 unknowns. It is merely asking whether we can get to another equation.
Question stem says:
3c+5b+5i=195

To find out:
7c+11b+9i=?=x(say)

(A) 3c+5b+5i=195
5c+7b+3i=217

So there must be numbers m and n (say), such that
m(3c+5b+5i-195) + n(5c+7b+3i-217) = 7c+11b+9i-x
If we equate LHS and RHS we get 3 equations -
3m+5n=7 .......(i),
5m+7n=11......(ii),
5m+3n=9......(iii)
From (ii) & (iii) m =3/2, n=1/2
Putting the value of m and n in (i) to check if it satisfies. Yes it does. So m and n are unique solutions. So we can get to 7c+11b+9i from the given information.

For those who want to know how, here it is -
5c+7b+3i=217
3c+5b+5i=195
-----------------
2c+2b-2i=22 (by subtraction)
c+b-i=11........(iv)

Again,
5c+7b+3i=217
3c+5b+5i=195
-----------------
8c+12b+8i=412 (by addition)....(v)

By (v)-(iv)
8c+12b+8i=412
c+b-i=11
-----------------
7c+11b+9i=401 (answer)

(B) Exactly employing the same method as we did in A, we get 3 equations
4m+3n=7..........(vi)
11m+5n=11..........(vii)
3m+5n=9..............(viii)

From (vii) & (viii) we get m=1/4 and n=33/20
We put these values in (vi) and it does not satisfy.
Therefore we do not have a unique solution. Hence we would not be able to get to 7c+11b+9i from the given information

Answer: A

The cost of 3 chocolates, 5 biscuits, and 5 ice creams is 195. What is the cost of 7 chocolates, 11 biscuits and 9 ice creams?

(1) The cost of 5 chocolates, 7 biscuits and 3 ice creams is 217.
(2) The cost of 4 chocolates, 1 biscuit and 3 ice creams is 141.

stem: 3c+5b+5i = 195....7c+11b+9i=?
1) 5c+7b+3i=217, left with 2 variables to solve not suffiicient
2) 4c+1b+3i=141, left with 2 variables to solve not sufficient
1+2,
can be solvable.
Ans C

If \(3c+5b+5i=195\), what is the value of \(7c+11b+9i\)?

Statement 1: \(5c+7b+3i=217\)
Multiplying \(3c+5b+5i=195\) by 3, we get:
\(9c+15b+15i=585\)

Adding together \(9c+15b+15i=585\) and \(5c+7b+3i=217\), we get:
\(14c+22b+18i=802\)
\(7c+11b+9i=401\)
SUFFICIENT.

Statement 2: \(4c+b+3i=141\)
Adding together \(3c+5b+5i=195\) and \(4c+b+3i=141\), we get:
\(7c+6b+8i=336\)
No way to determine the value of \(7c+11b+9i\).
INSUFFICIENT.



One way to prove that S2 is INSUFFICIENT:

Case 1: c=15
Statement 2 equation --> \(4*15+b+3i=141\) --> \(b+3i=81\)
Prompt equation --> \(3*15+5b+5i=195\) --> \(5b+5i=150\) --> \(b+i=30\)
Subtracting the prompt equation from the Statement 2 equation, we get:
\(2i=51\)
\(i=25.5\)
Since \(b+i=30\), \(b=4.5\)
In this case, \(7c+11b+9i=(7*15)+(11*4.5)+(9*25.5)=105+49.5+229.5=384\)

Case 1: c=25
Statement 2 equation --> \(4*25+b+3i=141\) --> \(b+3i=41\)
Prompt equation --> \(3*25+5b+5i=195\) --> \(5b+5i=120\) --> \(b+i=24\)
Subtracting the prompt equation from the Statement 2 equation, we get:
\(2i=17\)
\(i=8.5\)
Since \(b+i=24\), \(b=15.5\)
In this case, \(7c+11b+9i=(7*25)+(11*15.5)+(9*8.5)=175+170.5+76.5=422\)

Since \(7c+11b+9i\) can be different values, INSUFFICIENT.

3 chocolates+5 biscuits+5 ice creams =195.
7 chocolates+11 biscuits+9 ice creams=?

(1) The cost of 5 chocolates, 7 biscuits and 3 ice creams is 217.

3 chocolates+5 biscuits+5 ice creams =195
5 chocolates+7 biscuits+3 ice creams=217

adding both we get, 8 chocolates+12 biscuits+8 ice creams=412
subtracting both , -1 chocolates -1 biscuits+1 ice creams=-11

adding above we get the required value.....................SUFFICIENT



(2) The cost of 4 chocolates, 1 biscuit and 3 ice creams is 141.

even after adding and subtracting we wont be getting the required value...........INSUFFICIENT

OA:A

Given: 3c + 5b + 5i = 195

Question: 7c + 11b + 9i = ?

STatement 1: 5c + 7b + 3i = 217

Multiplying by 3 both sides in 3c + 5b + 5i = 195
3c + 15b + 15i = 585

Adding 5c + 7b + 3i = 217 in above equation

(9c + 15b + 15i) + (5c + 7b + 3i) = 585+217

14c + 22b + 18i = 802

Dividing by 2 both sides

7c + 11b + 9i = 401

SUFFICIENT

STatement 2: 4c + 1b + 3i = 143

NOT SUFFICIENT

Answer: Option A

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