7th Grade > Mathematics
RATIONAL NUMBERS MCQs
Total Questions : 120
| Page 1 of 12 pages
Answer: Option C. -> =
:
C
Reducing 3926 to its lowest form , we get,
39÷1326÷13 =32( 13 is the common factor)
Multiplying numerator and denominator by 2 we get
3×22×2 = 64
Hence,3926 is also equal to 64
So, both the fraction are equal
Hence, 3926=64
:
C
Reducing 3926 to its lowest form , we get,
39÷1326÷13 =32( 13 is the common factor)
Multiplying numerator and denominator by 2 we get
3×22×2 = 64
Hence,3926 is also equal to 64
So, both the fraction are equal
Hence, 3926=64
:
(a) Answer: 1 Mark
(b) Steps: 1 Mark
Result: 1 Mark
(a) Each corner has three mutually perpendicular edges, hence forming three right angles in each corner. A room has 8 corners. Hence, there are 24 right angles in the room.
(b) Let the number to be subtracted be x.
⇒512+32−x=2
⇒5+1812−x=2
⇒2312−x=2
⇒x=2312−2
⇒x=23−2412
⇒x=−112
⇒x=−112
Answer: Option A. -> −2857
:
A
−819+−457=(−8×3)(19×3)+−457
=−2457+−457
=−2857
:
A
−819+−457=(−8×3)(19×3)+−457
=−2457+−457
=−2857
Answer: Option C. -> 3663
:
C
Consider given rational number47.
To make the denominator as 63, we have to multiply it with 9.
Multiplying both numerator and denominator by 9, we get
4×97×9=3663
Therefore, 3663 is anequivalent rational number of47 with denominator equal to 63.
:
C
Consider given rational number47.
To make the denominator as 63, we have to multiply it with 9.
Multiplying both numerator and denominator by 9, we get
4×97×9=3663
Therefore, 3663 is anequivalent rational number of47 with denominator equal to 63.
Answer: Option C. -> −718
:
C
Note that LCM of 9, 12, 18, 3 is 36.
Using LCM to convert each of the given rational numbers to equivalent forms,
−49 = −1636
−512 = −1536
−718 = −1436
−23 = −2436
Since the denominators are equal, we now compare the rational numbers using its numerators.
Thus, −2436<−1636<−1536<−1436
i.e., −23<−49<−512<−718
∴−718 is the greatest among the given options.
:
C
Note that LCM of 9, 12, 18, 3 is 36.
Using LCM to convert each of the given rational numbers to equivalent forms,
−49 = −1636
−512 = −1536
−718 = −1436
−23 = −2436
Since the denominators are equal, we now compare the rational numbers using its numerators.
Thus, −2436<−1636<−1536<−1436
i.e., −23<−49<−512<−718
∴−718 is the greatest among the given options.
Answer: Option B. -> False
:
B
12 × 9 = 108
⇒10812=(12×9)12
= 9
:
B
12 × 9 = 108
⇒10812=(12×9)12
= 9
Answer: Option B. -> −56
:
B
Reciprocal of−23is−32.
23−32=46−96=(4−9)6=−56
[LCM of 2 and 3 is 6]
:
B
Reciprocal of−23is−32.
23−32=46−96=(4−9)6=−56
[LCM of 2 and 3 is 6]
Answer: Option D. -> −413
:
D
Reciprocal of −2612 is −1226.
213+−1226 [Taking LCM]
=426−1226=4−1226=−826=−413
:
D
Reciprocal of −2612 is −1226.
213+−1226 [Taking LCM]
=426−1226=4−1226=−826=−413
:
Each part: 1 Mark
(a) Additive inverse of314=−314
Additive inverse of −519=519
(b)Multiplicative inverse of −34=4−3
:
Each part: 1 Mark
(a) −311+−14+58
−3×888−1×2288+5×1188
−24−22+5588
−46+5588=988
(b) −59+−712+1118
−5×436−7×336+11×236
−20−21+2236=−1936