Number System - Study Mode

[#401] 8888 + 848 + 88 - ? = 7337 + 737
Correct Answer

(D) 1750

Explanation

Solution: Let, 8888 + 848 +88 - x = 7337 + 737 Then, 9824 - x = 8074 x = 9824 - 8074 x = 1750

[#402] What least value must be assigned to '*' so that the number 63576 * 2 is divisible by 8 ?
Correct Answer

(C) 3

Explanation

Solution: For divisibility by 8, last 3 number should be divisible by 8. Now, put the value 0, 1 ... 2 ... and check. When use * = $$frac{632}{8}$$ = 79 So, hence it is divisible by 8
answer is 3

[#403] The number 1, 3, 5, 7. . . . . 99 and 128 are multiplied together. The number of zeros at the end of the product must be -
Correct Answer

(C) 7

Explanation

Solution: →( 1, 3, 5, 7. . . . . 99 ) × 128 5 → 5 1 15 → 5 1 25 → 5 2 35 → 5 1 45 → 5 1 55 → 5 1 65 → 5 1 75 → 5 2 85 → 5 1 95 → 5 1 × 128 → 2 7 5 12 + 2 7 will make zero but since 2 comes 7 times, so only 7 zero will come.

[#404] The largest among the numbers ?
Correct Answer

(C) 0.12

Explanation

Solution: (0.1) 2 → .01 $$sqrt {0.0121} $$ → 0.11 0.12 → 0.12 → Largest $$sqrt {.0004} $$ → 0.02

[#405] The product of two numbers is 120 and the sum of their squares is 289. The sum of the two number is -
Correct Answer

(A) 23

Explanation

Solution: Let the two number are a and b According to question, $$eqalign{
& {a^2} + {b^2} = 289 cr
& ab{ ext{ }} = { ext{ }}120 cr
& {left( {a + b}
ight)^2} = {a^2} + {b^2} + 2ab cr
& {left( {a + b}
ight)^2} = {left( {289}
ight)^2} + left( {2 imes 120}
ight) cr
& {left( {a + b}
ight)^2} = 529 cr
& left( {a + b}
ight) = 23 cr} $$