CAT 2024 Slot 1 · DILR · Set 4: Stars Given by Web Surfers to Bloggers

The full set and all 4 questions (Q15–Q18) from CAT 2024 Slot 1, with answers and solutions.

Six web surfers M, N, O, P, X, and Y each had 30 stars which they distributed among four bloggers A, B, C, and D. The number of stars received by A and B from the six web surfers is shown in the figure below.

The following additional facts are known regarding the number of stars received by the bloggers from the surfers.

1. The numbers of stars received by the bloggers from the surfers were all multiples of 5 (including 0).

2. The total numbers of stars received by the bloggers were the same.

3. Each blogger received a different number of stars from M.

4. Two surfers gave all their stars to a single blogger.

5. D received more stars than C from Y.

Question 15 · Reasoning Based DI

What was the total number of stars received by D?

Answer & solution

Answer: 45

Solving the set

Step 1 – Total stars = 6 × 30 = 180. All four bloggers received the same number (fact 2), so each received 180/4 = 45. From the chart, A got 10 + 25 + 0 + 5 + 0 + 5 = 45 and B got 0 + 0 + 0 + 25 + 0 + 20 = 45, which confirms it.

Step 2 – Find what each surfer had left for C and D.

Surfer

M

N

O

P

X

Y

Total

Total stars

30

30

30

30

30

30

180

Given to A

10

25

0

5

0

5

45

Given to B

0

0

0

25

0

20

45

Left for C + D

20

5

30

0

30

5

90

Step 3 – Fact 4 (two surfers gave all 30 to one blogger). M, N, P and Y each gave stars to A or B and still had some left, or split between A and B, so none of them gave all 30 to one blogger. Hence O and X are the two surfers, and each gave all 30 to C or to D.

Step 4 – O and X cannot both give to the same blogger (that blogger would get 60 > 45). So one of them gave 30 to C and the other 30 to D. Which one went to which cannot be decided.

Step 5 – Surfer M (fact 3). A got 10 and B got 0, so C and D share 20, using values different from 0 and 10 and from each other (multiples of 5). The only possible pair is 15 and 5.

Step 6 – Surfer Y (fact 5). C and D share 5 and D got more, so D = 5 and C = 0.

Step 7 – Totals of C and D. Each needs 45. C already has 30 (from O or X) + 0 (P) + 0 (Y), so C needs 15 from M and N together. D has 30 + 0 + 5 = 35, so D needs 10 from M and N together. N has only 5 for C and D. If C took 5 from M, it would need 10 from N (impossible). So C gets 15 from M and 0 from N, and D gets 5 from M and 5 from N.

Blogger

M

N

O

P

X

Y

Total

A

10

25

0

5

0

5

45

B

0

0

0

25

0

20

45

C

15

0

30 or 0

0

0 or 30

0

45

D

5

5

0 or 30

0

30 or 0

5

45

Bloggers who got stars

3

2

1

2

1

3

 

This question

From Step 1, each blogger received 180/4 = 45 stars. So D received 45.

Hence, the answer is 45.

Question 16 · Reasoning Based DI

What was the number of stars received by D from Y?

  1. A

    Cannot be determined

  2. B

    5

  3. C

    0

  4. D

    10

Pick an option, then check.
Answer & solution

Answer: Option B

Solving the set

Step 1 – Total stars = 6 × 30 = 180. All four bloggers received the same number (fact 2), so each received 180/4 = 45. From the chart, A got 10 + 25 + 0 + 5 + 0 + 5 = 45 and B got 0 + 0 + 0 + 25 + 0 + 20 = 45, which confirms it.

Step 2 – Find what each surfer had left for C and D.

Surfer

M

N

O

P

X

Y

Total

Total stars

30

30

30

30

30

30

180

Given to A

10

25

0

5

0

5

45

Given to B

0

0

0

25

0

20

45

Left for C + D

20

5

30

0

30

5

90

Step 3 – Fact 4 (two surfers gave all 30 to one blogger). M, N, P and Y each gave stars to A or B and still had some left, or split between A and B, so none of them gave all 30 to one blogger. Hence O and X are the two surfers, and each gave all 30 to C or to D.

Step 4 – O and X cannot both give to the same blogger (that blogger would get 60 > 45). So one of them gave 30 to C and the other 30 to D. Which one went to which cannot be decided.

Step 5 – Surfer M (fact 3). A got 10 and B got 0, so C and D share 20, using values different from 0 and 10 and from each other (multiples of 5). The only possible pair is 15 and 5.

Step 6 – Surfer Y (fact 5). C and D share 5 and D got more, so D = 5 and C = 0.

Step 7 – Totals of C and D. Each needs 45. C already has 30 (from O or X) + 0 (P) + 0 (Y), so C needs 15 from M and N together. D has 30 + 0 + 5 = 35, so D needs 10 from M and N together. N has only 5 for C and D. If C took 5 from M, it would need 10 from N (impossible). So C gets 15 from M and 0 from N, and D gets 5 from M and 5 from N.

Blogger

M

N

O

P

X

Y

Total

A

10

25

0

5

0

5

45

B

0

0

0

25

0

20

45

C

15

0

30 or 0

0

0 or 30

0

45

D

5

5

0 or 30

0

30 or 0

5

45

Bloggers who got stars

3

2

1

2

1

3

 

This question

From Step 6, Y gave 5 stars in all to C and D, and D received more than C. So D received 5 and C received 0.

Hence, the answer is option 2.

Question 17 · Reasoning Based DI

How many surfers distributed their stars among exactly 2 bloggers?

Answer & solution

Answer: 2

Solving the set

Step 1 – Total stars = 6 × 30 = 180. All four bloggers received the same number (fact 2), so each received 180/4 = 45. From the chart, A got 10 + 25 + 0 + 5 + 0 + 5 = 45 and B got 0 + 0 + 0 + 25 + 0 + 20 = 45, which confirms it.

Step 2 – Find what each surfer had left for C and D.

Surfer

M

N

O

P

X

Y

Total

Total stars

30

30

30

30

30

30

180

Given to A

10

25

0

5

0

5

45

Given to B

0

0

0

25

0

20

45

Left for C + D

20

5

30

0

30

5

90

Step 3 – Fact 4 (two surfers gave all 30 to one blogger). M, N, P and Y each gave stars to A or B and still had some left, or split between A and B, so none of them gave all 30 to one blogger. Hence O and X are the two surfers, and each gave all 30 to C or to D.

Step 4 – O and X cannot both give to the same blogger (that blogger would get 60 > 45). So one of them gave 30 to C and the other 30 to D. Which one went to which cannot be decided.

Step 5 – Surfer M (fact 3). A got 10 and B got 0, so C and D share 20, using values different from 0 and 10 and from each other (multiples of 5). The only possible pair is 15 and 5.

Step 6 – Surfer Y (fact 5). C and D share 5 and D got more, so D = 5 and C = 0.

Step 7 – Totals of C and D. Each needs 45. C already has 30 (from O or X) + 0 (P) + 0 (Y), so C needs 15 from M and N together. D has 30 + 0 + 5 = 35, so D needs 10 from M and N together. N has only 5 for C and D. If C took 5 from M, it would need 10 from N (impossible). So C gets 15 from M and 0 from N, and D gets 5 from M and 5 from N.

Blogger

M

N

O

P

X

Y

Total

A

10

25

0

5

0

5

45

B

0

0

0

25

0

20

45

C

15

0

30 or 0

0

0 or 30

0

45

D

5

5

0 or 30

0

30 or 0

5

45

Bloggers who got stars

3

2

1

2

1

3

 

This question

From the final table, the number of bloggers who received stars from each surfer is: M 3 (A, C, D), N 2 (A, D), O 1, P 2 (A, B), X 1, Y 3 (A, B, D).

Exactly two bloggers: N and P, i.e., 2 surfers.

Hence, the answer is 2.

Question 18 · Reasoning Based DI

Which of the following can be determined with certainty?

I. The number of stars received by C from M

II. The number of stars received by D from O

  1. A

    Only I

  2. B

    Both I and II

  3. C

    Only II

  4. D

    Neither I nor II

Pick an option, then check.
Answer & solution

Answer: Option A

Solving the set

Step 1 – Total stars = 6 × 30 = 180. All four bloggers received the same number (fact 2), so each received 180/4 = 45. From the chart, A got 10 + 25 + 0 + 5 + 0 + 5 = 45 and B got 0 + 0 + 0 + 25 + 0 + 20 = 45, which confirms it.

Step 2 – Find what each surfer had left for C and D.

Surfer

M

N

O

P

X

Y

Total

Total stars

30

30

30

30

30

30

180

Given to A

10

25

0

5

0

5

45

Given to B

0

0

0

25

0

20

45

Left for C + D

20

5

30

0

30

5

90

Step 3 – Fact 4 (two surfers gave all 30 to one blogger). M, N, P and Y each gave stars to A or B and still had some left, or split between A and B, so none of them gave all 30 to one blogger. Hence O and X are the two surfers, and each gave all 30 to C or to D.

Step 4 – O and X cannot both give to the same blogger (that blogger would get 60 > 45). So one of them gave 30 to C and the other 30 to D. Which one went to which cannot be decided.

Step 5 – Surfer M (fact 3). A got 10 and B got 0, so C and D share 20, using values different from 0 and 10 and from each other (multiples of 5). The only possible pair is 15 and 5.

Step 6 – Surfer Y (fact 5). C and D share 5 and D got more, so D = 5 and C = 0.

Step 7 – Totals of C and D. Each needs 45. C already has 30 (from O or X) + 0 (P) + 0 (Y), so C needs 15 from M and N together. D has 30 + 0 + 5 = 35, so D needs 10 from M and N together. N has only 5 for C and D. If C took 5 from M, it would need 10 from N (impossible). So C gets 15 from M and 0 from N, and D gets 5 from M and 5 from N.

Blogger

M

N

O

P

X

Y

Total

A

10

25

0

5

0

5

45

B

0

0

0

25

0

20

45

C

15

0

30 or 0

0

0 or 30

0

45

D

5

5

0 or 30

0

30 or 0

5

45

Bloggers who got stars

3

2

1

2

1

3

 

This question

Statement I: From Step 7, C received exactly 15 stars from M. This is determined.

Statement II: From Step 4, one of O and X gave 30 to D, but we cannot tell which. So D received either 0 or 30 from O. This is not determined.

Only statement I can be determined.

Hence, the answer is option 1.

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