Page 46 - CT&AI_CLasa_7_Part_1

Finding common

3 Ground

computational thinking quest

Tick ( ) the correct option.

1. Given HCF(x, y) = 10, what is the minimum 5. Two robots start at the same point on a
possible value for LCM(x, y), if x and y are circular track. Robot A completes a lap in 48
distinct multiples of 10? (Logical Thinking) seconds, and Robot B completes a lapin 60
seconds. What is the time (in seconds) after
(a) 10 (b) 20
which their cycles synchronize?

(c) 30 (c) 60 (Algorithmic Thinking)
2. A student writes a code to find the HCF of any (a) 120 sec
two numbers. The code always returns the
smaller of the two numbers. For which pair (b) 240 sec
will this code produce an incorrect result?

(Analytical Thinking) (c) 360 sec

(a) (12, 18) (b) (10, 20) (d) 480 sec
6. A car is racing a bike. The bike has a head
(c) (5, 25) (d) (100, 500)
start of 100 meters. For every 8 meters the
3. In some basic cryptography, the HCF of a bike travels, the car covers 10 meters. In how
"Key" and a "Message" must be 1 to ensure many meters does the car catch up with the
security. If the Message is 120, which Key bike? (Analytical Thinking)
would be "secure"? (Logical Thinking)
(a) 400 (b) 500
(a) 45 (b) 48
(c) 600 (d) 700
(c) 49 (d) 50
7. A security key is generated by taking the LCM
4. If the HCF of L and W is H, how many square of two distinct prime numbers p and q. If an
tiles of side H are needed to cover an area of attacker knows the LCM is 1147, how many
rectangle of dimension L × W? unique pairs of (p, q) could have generated
(Analytical Thinking) this key (excluding order)?

L × W L × W (Analytical Thinking)
(a) (b)
H H × H (a) 1 (b) 2

(c) L + W (d) LCM (L, W)
H H (c) 3 (d) 4

44 Computational Thinking-7 (Mathematics)