Quantitative Aptitude
Sample Paper 10
See Answer
(1): (c) 28, (2): (d) 64 sq cm, (3): (b) 588885, (4): (a) 12, (5): (c) 26, (6): (b) 7th, (7): (c) 360
Explanation:
Question 1: A beats B by 10 m means when A covers 100 m, then B covers 90 m
B beats C by 20 m means when B covers 100 m, then C covers 80 m.
So, when B covers 90 m, then C covers 80 ÷ 100 × 90 = 72 m
So, when A covers 100 m, then B covers 90 m and C covers 72 m
So, A beats C by 100 – 72 = 28 m
Question 2: Total surface area of pyramid = (1/2) P × l + B
Where; P is perimeter of base, l is slant height and B is area of base
Perimeter of base = 4 × 4 = 16 cm
Area of base = 42 = 16 sq cm
So, total surface area = (1/2) × 16 × 6 + 16
= 48 + 16 = 64 sq cm
Question 3: If the difference between sum of numbers at odd places and sum of numbers at even places of a number is either zero or divisible by 11 then the number is divisible by 11.
For 588885:
Sum of numbers at odd places = 5 + 8 + 8 = 21
Sum of numbers at even places = 8 + 8 + 5 = 21
Difference between sums = 21 – 21 = 0
So, 588885 is divisible by 11
Question 4: As a woman works half fast as a man so 6 women would complete the work in 2 × 10 = 20 days
So, time taken by 10 women = 6 × 20 ÷ 10 = 12 days
Question 5: As the sum is zero so sum of two groups of number would be equal but of opposite signs, i.e. positive and negative numbers.
Number of terms = 51
So, sum of 25 terms = negative of sum of another group of 25 terms
The middle term, i.e 26th term = zero
Question 6: This is a rule of thumb that money becomes double at 10% per annum compounded annually.
You can cross check this by applying the formula for compound interest:
If principal = 100
Then A = 100 × ((1+10)/(100))7
= 100 × (11/10)7
= 100 × 1.9487 = 200 (approx.)
Question 7: Possible number of ways = 6 × 5 × 4 × 3 = 360
First person can be seated in 6 ways, 2nd person in 5 ways, 3rd person in 4 ways and 4th person can be seated in 3 ways.