Question

Brain Study Puzzle No 35
1. How many seconds are there in a day?
(A). 82,400 (B). 85,400 (C). 88,400 (D).86,400
2. Sam is 11 years old. Ross is twice as old as
Sam. When Ross is 50 years old, how old will
Sam be?
(A). 39 (B). 41 (C). 43 (D). 38
3. A car covers 7 feet in 1/3 of a second. How
far will it go in 5 seconds?
(A). 100 feet (B). 105 feet
(C). 80 feet (D). 110 feet
4.17 out of 20 respiratory diseases are
curable. What percentage is curable?
(A). 85% (B). 82% (C). 80% (D). 70%
5.Which of these is not a whole number
followed by its square?
(A). 11.121 (B). 2,4 (C). 13, 169 (D).15, 205
6. Identify the next number in the series.
1,4,3, 8, 21,
(A). 160 (B). 16 (C). 17 (D). 121
7.A girl is 17 years old. Her brother is twice her
age. When the girl is 23 years old, what will be
the age of the boy?
(A). 48 (B). 46 (C). 42 (D).40
8.A car travels 5 feet in 0.5 seconds. How far
will it go in a minute?
(A).900 feet (B).150 feet (C). 500 feet (D).600​

Answer 1

Answer:

1. 86400

2. 39 years

3. 105 feet

4. 85%

5. 15, 205

6. 17

7. 40 years

8. 600 metres

Answer 2

1.  (D) 86,400

A day contains 24 hours, an hour contains 60 minutes, and a minute contains 60 seconds.

2.  (A) 39

Difference between ages of Sam and Ross is 11. (Don't get mistaken that Ross's age becomes twice for 1 year, when compared to Sam!)

3.  (B) = 105 feet

That car covers 21 feet in 1 second.

4.  (A) 85%

(17 / 20) × 100 = 85%.

5.  (D) 15, 205

The square of 15 is 225.

6.  (A) 160

This one seems much tougher. The algebraic form of this sequence is,

$a_n=a_n\times a_{n+1}-a_{n+2}$

So,

1 × 4 - 3 = 1

4 × 3 - 8 = 4

3 × 8 - 21 = 3

Let our number (the answer) be x.

    8 × 21 - x = 8

⇒  x = 8 × 21 - 8

⇒  x = 8 × 20

⇒  x = 160

7.  (D) 40.

Difference between their ages is 17.

8.  (D) 600 feet

Well, this car travels 10 feet in 1 second.