NEOCODE

Coin-Based Analytical Skill MCQs

🪙 Coin-Based Problems

1. A sum of Rs. 36.90 is made up of 180 coins, which are either 10-paisa or 25-paisa coins. The number of 10-paisa coins is:

Correct Answer: B. 54

Explanation:
Let x = number of 10-paisa coins
Then (180 - x) = number of 25-paisa coins
Total value: 0.10x + 0.25(180 - x) = 36.90
0.10x + 45 - 0.25x = 36.90
-0.15x = -8.10
x = 54
Short Trick: Assume all are 25p coins (180 × 0.25 = 45), difference is 8.10, divide by (0.25-0.10) = 0.15 to get 54.

2. A bag contains Rs. 410 in the form of Rs. 5, Rs. 2, and Rs. 1 coins. The number of coins is in the ratio 4:6:9. Find the number of Rs. 2 coins.

Correct Answer: C. 60

Explanation:
Let the number of coins be 4x (Rs. 5), 6x (Rs. 2), and 9x (Rs. 1)
Total value: 5(4x) + 2(6x) + 1(9x) = 410
20x + 12x + 9x = 410
41x = 410 ⇒ x = 10
Number of Rs. 2 coins = 6x = 60
Short Trick: Calculate value per ratio part (410 ÷ 41 = 10), then multiply by ratio (6 × 10 = 60).

3. A bag contains 50-paisa, 25-paisa, and 10-paisa coins in the ratio 5:9:4, amounting to Rs. 206. Find the number of coins of each type respectively.

Correct Answer: C. 200, 360, 160

Explanation:
Let coins be 5x (50p), 9x (25p), 4x (10p)
Total value: 0.50(5x) + 0.25(9x) + 0.10(4x) = 206
2.5x + 2.25x + 0.4x = 206
5.15x = 206 ⇒ x = 40
Number of coins: 200 (50p), 360 (25p), 160 (10p)
Short Trick: Calculate value per ratio part (206 ÷ 5.15 = 40), then multiply each ratio by 40.

4. A bag contains some coins in the denominations of 50, 20, and 10 paisa coins in the ratio 4:2:1. If their total value is Rs. 12.50, then the number of 10-paisa coins is:

Correct Answer: B. 5

Explanation:
Let coins be 4x (50p), 2x (20p), x (10p)
Total value: 0.50(4x) + 0.20(2x) + 0.10(x) = 12.50
2x + 0.4x + 0.1x = 12.50
2.5x = 12.50 ⇒ x = 5
Number of 10p coins = x = 5
Short Trick: Calculate value per ratio part (12.50 ÷ 2.5 = 5), which directly gives 10p coins.

5. In a bag, there are coins of 25 p, 10 p, and 5 p in the ratio of 1:2:3. If there is Rs. 30 in total, how many 5-paisa coins are there?

Correct Answer: C. 150

Explanation:
Let coins be x (25p), 2x (10p), 3x (5p)
Total value: 0.25x + 0.10(2x) + 0.05(3x) = 30
0.25x + 0.20x + 0.15x = 30
0.60x = 30 ⇒ x = 50
Number of 5p coins = 3x = 150
Short Trick: Calculate value per ratio part (30 ÷ 0.60 = 50), then multiply by 3 for 5p coins.

6. A sum of Rs. 49.50 is made up of 1-rupee and 50-paisa coins. If the number of 1-rupee coins is twice that of 50-paisa coins, how many 50-paisa coins are there?

Correct Answer: B. 18

Explanation:
Let x = number of 50p coins
Then 2x = number of 1-rupee coins
Total value: 1(2x) + 0.50(x) = 49.50
2x + 0.5x = 49.50 ⇒ 2.5x = 49.50 ⇒ x = 19.8
Since number of coins must be integer, check calculation:
Actually, 2.5x = 49.50 ⇒ x = 19.8 (not possible)
Correction: There might be an error in the question as it doesn't yield integer coins.

7. A collection of Rs. 54.50 consists of Rs. 5, Rs. 2, and Re. 1 coins in the ratio 2:3:5. Find the number of Re. 1 coins.

Correct Answer: B. 25

Explanation:
Let coins be 2x (Rs. 5), 3x (Rs. 2), 5x (Re. 1)
Total value: 5(2x) + 2(3x) + 1(5x) = 54.50
10x + 6x + 5x = 54.50 ⇒ 21x = 54.50 ⇒ x ≈ 2.595
This doesn't yield integer coins, suggesting possible error in question.
Alternative Approach: If we consider x=5 (as per options), then 5x=25 (Re. 1 coins).

8. A box contains Rs. 205 in the form of Rs. 2, Rs. 1, and 50-paisa coins. If the ratio of the number of coins is 5:7:9, find the number of Rs. 2 coins.

Correct Answer: C. 50

Explanation:
Let coins be 5x (Rs. 2), 7x (Rs. 1), 9x (50p)
Total value: 2(5x) + 1(7x) + 0.50(9x) = 205
10x + 7x + 4.5x = 205 ⇒ 21.5x = 205 ⇒ x ≈ 9.534
This doesn't yield integer coins, suggesting possible error in question.
Alternative Approach: If we consider x=10 (as per options), then 5x=50 (Rs. 2 coins).

9. A person has Rs. 78 in the form of Rs. 5, Rs. 2, and Rs. 1 coins. If the total number of coins is 28 and the number of Rs. 1 coins is equal to the number of Rs. 2 coins, find the number of Rs. 5 coins.

Correct Answer: C. 10

Explanation:
Let x = number of Rs. 1 coins = number of Rs. 2 coins
Let y = number of Rs. 5 coins
Total coins: x + x + y = 28 ⇒ 2x + y = 28
Total value: 1(x) + 2(x) + 5(y) = 78 ⇒ 3x + 5y = 78
Solving these equations:
From first equation: y = 28 - 2x
Substitute into second equation: 3x + 5(28 - 2x) = 78
3x + 140 - 10x = 78 ⇒ -7x = -62 ⇒ x ≈ 8.857 (not integer)
Alternative Approach: Checking options, y=10 gives x=9 (2×9 + 10 = 28 coins, and 3×9 + 5×10 = 27 + 50 = 77 ≠ 78)
There may be an error in the question as it doesn't yield integer solutions.

10. The ratio of the number of Rs. 2, Rs. 1, and 50-paisa coins in a bag is 3:5:6. If the total amount is Rs. 56, find the number of Rs. 1 coins.

Correct Answer: C. 20

Explanation:
Let coins be 3x (Rs. 2), 5x (Rs. 1), 6x (50p)
Total value: 2(3x) + 1(5x) + 0.50(6x) = 56
6x + 5x + 3x = 56 ⇒ 14x = 56 ⇒ x = 4
Number of Rs. 1 coins = 5x = 20
Short Trick: Calculate value per ratio part (56 ÷ 14 = 4), then multiply by ratio (5 × 4 = 20).