Page 33 - CT&AI_CLasa_7_Part_1

7. Sujoy is filling a magic box where the sum 9. Rahul is replacing each letter with a suitable
of all rows, columns, and diagonals must be number in each box of the magic square.
18. He filled the numbers in the 3 × 3 grid but What is the value of B + E more than D − C?
made a mistake. (Analytical Thinking)

9 2 7 8 1 A
6 4 8 B 5 C

5 10 3 D E F

Which correction will make the magic box
correct? (Decomposition) (a) 9 (b) – 1
(a) Interchange 3 and 10 (c) 2 (d) 0
10. Rohan has some coins in his piggy bank. He
(b) Interchange 6 and 4 has:
• an even number of `1 coins,
(c) Interchange 2 and 7
• an odd number of `2 coins, and
(d) Interchange 5 and 9 • an odd number of `5 coins.
After counting, he says that the total amount
8. In how many ways can the number 10001 be of money is `48. Is his statement correct?
written as a sum of two primes? (Algorithmic Thinking)
(Critical Thinking)
(a) Yes, because the total can be even.
(a) 1
(b) No, because the total must always
(b) 2 be odd.
(c) Yes, because the number of coins
(c) 0 does not affect the total.

(d) More than 2 (d) Cannot be determined.

In a sequence of six doors, each door has a doorbell on right side. Pressing
the doorbell, a door opens the adjacent doors only (left and right). What is the
minimum number of doorbell you need to press to open all the doors?

(a) 2 (b) 4

(c) 3 (d) 5

Number Play 31