Mathematical operation and symbol notation
- If '-' stands for '÷', '+' stands for 'x', '÷' stands for '-' and 'x' stands for '+', find out which one is correct?
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Try All option one by one
Correct Option: B
From option (b),
49 - 7 + 3 ÷ 5 x 8 = 24
Change the sign, as per the question,
49 ÷ 7 x 3 - 5 + 8 = 24
⇒ 7 x 3 - 5 + 8 = 24
⇒ 21 - 5 + 8 = 24
∴ 24 = 24
- If '+' mean '-', '-' means 'x', 'x' means '÷' and '÷' means '+', then value of 16 x 2 ÷ 25 + 7 - 4 is
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16 x 2 ÷ 25 + 7 - 4
= 16 ÷ 2 + 25 - 7 x 4
Correct Option: B
16 x 2 ÷ 25 + 7 - 4
= 16 ÷ 2 + 25 - 7 x 4
= 8 + 25 - 28
= 25 - 20 = 5
Direction: In each of the following questions, two rows of numbers are given. The resultant number in each row is to be worked out separately based on the following rules and the questions below the rows of number are to be answered. The operations of numbers progress from left to the right.
Rules
(i) If a two-digit number is followed by another even number, the first one is to be divided by the second one.
(ii) If an even number is followed by a prime number, the two are to be multiplied.
(iii) If an odd number is followed by another odd number, the two are to be added.
(iv) if a three-digit number is followed by a two-digit number which is a perfect square, the second number is to be subtracted from the first number.
(v) If a three-digit number is followed by a two-digit number which is not a perfect square, the first number is to be divided by the second one.
- 84 14 13
360 24 17
What is the difference between the resultant of the first row and the second row ?
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Rules
(i) (2-digit even number) ÷ ( Even number)
(ii) (Even number) x (Prime number)
(iii) (Odd number) + (Odd number)
(iv) (3-digit number) - (2-digit perfect square number)
(v) (3-digit number) ÷ (2-digit non-perfect square number)
Hint
1st Row 84 14 13 ⇒ 84 ÷ 14 = 6 [rule (i)]Correct Option: B
Rules
(i) (2-digit even number) ÷ ( Even number)
(ii) (Even number) x (Prime number)
(iii) (Odd number) + (Odd number)
(iv) (3-digit number) - (2-digit perfect square number)
(v) (3-digit number) ÷ (2-digit non-perfect square number)
Solution
1st Row 84 14 13 ⇒ 84 ÷ 14 = 6 [rule (i)]
⇒ 6 x 13 = 78 [rule (ii)]
2nd Row 360 24 17 ⇒ 360 ÷ 24 = 15 [rule (v)]
⇒ 15 + 17 = 32 [rule (iii)]
∴ Resultant difference = 78 - 32 = 46
Direction: In each of the following questions, two rows of numbers are given. The resultant number in each row is to be worked out separately based on the following rules and the questions below the rows of number are to be answered. The operations of numbers progress from left to the right.
Rules
(i) If an odd number is followed by another composite odd number, they are to be multiplied.
(ii) If an even number is followed by an odd number, they are to be added.
(iii) If an even number is followed by a number which is the perfect square, the even number is to be subtracted from the perfect square.
(iv) if an odd number is followed by a prime odd number, the first number is to be divided by the second number.
(v) If an odd number is followed by an even number, the second one is to be subtracted from the first one.
- 14 5 9
24 w 88
If 'w' is the resultant of the first row, what will be the resultant of the second row ?
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Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) → (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Hint
1st Row 14 5 9 ⇒ 14 + 5 = 19 [rule (ii)]Correct Option: D
Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) → (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 14 5 9 ⇒ 14 + 5 = 19 [rule (ii)]
⇒ 19 x 9 = 171 [rule (i)]
= w
2nd Row 24 w 88 ⇒ 24 171 88
⇒ 24 + 171 = 195 [rule (ii)]
⇒ 195 - 88 = 107 [rule (v)]
∴ Resultant of second row = 107
- 73 34 13
32 p 15
If 'p' is the resultant of the first row, what will be the resultant of the second row ?
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Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) → (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Hint
1st Row 73 34 13 ⇒ 73 - 34 = 39 [rule (v)]Correct Option: D
Rules
(i) (Odd number) x (Composite odd number)
(ii) (Even number) + (Odd number)
(iii) (Even number) → (Perfect square number), then (Perfect square number) - (Even number)
(iv) (Odd number) ÷ (Prime odd number)
(v) (Odd number) - (Even number)
Solution
1st Row 73 34 13 ⇒ 73 - 34 = 39 [rule (v)]
⇒ 39 ÷ 13 = 3 = p [rule (iv)]
2nd Row 32 p 15 ⇒ 32 3 15
⇒ 32 + 3 = 35 [rule (ii)]
⇒ 35 x 15 = 255 [rule (i)]
∴ Resultant of second row = 525
