Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. | If a - b = 9 and a2 + b2 = 125, the what should be the value of ab ? |
| 1) | 16 | 2) | 18 |
| 3) | 20 | 4) | 22 |
| 5) | None of these | ||
Answer : 22
Explanation :
Explanation :
First Method::
We know that, 2ab = (a2 + b2) - (a - b)2 = 125 - 81 = 44 or ab = 22.
Second Method:
We know that, (a - b)2 = a2 + b2 -2ab = 125- 2ab or 81 = 125 -2ab or 2ab = 125-81 =44
or ab =44/2=22
View AnswerQ2. |
|
| 1) | 6050 | 2) | 10060 |
| 3) | 12040 | 4) | 24200 |
| 5) | None of these | ||
Answer : 24200
Explanation : We can express , (23+43+63+83+ 103+...............+203) =
Explanation : We can express , (23+43+63+83+ 103+...............+203) =
23 x (13+23+33+43+ 53+63+................+103) = 8 x 3025 = 24200
View AnswerQ3. | Given that, (12+22+32+42+ 52+62+72) = x +1 , the find the value of the following expressions: |
| 1) | 2(x+1) | 2) | 4(x+1) |
| 3) | 8(x+2) | 4) | 16(x+1) |
| 5) | None of these | ||
Answer : 4(x+1)
Explanation : We can write, (22+42+62+82+102+122+ 142) = 22 x (12+22+32+42+ 52+62+72) = 4(x+1)
Explanation : We can write, (22+42+62+82+102+122+ 142) = 22 x (12+22+32+42+ 52+62+72) = 4(x+1)
View AnswerQ4. | If a+1/a = 6 then, a4 +1/a4 = ? |
| 1) | 1154 | 2) | 1158 |
| 3) | 1160 | 4) | 1164 |
| 5) | None of these | ||
Answer : 1154
Explanation : Given, a+1/a = 6
Explanation : Given, a+1/a = 6
a2+1/a2 = (a +1/a)2 -2 = 36-2=34
or a4 +1/a4 = (a2+1/a2 )2 = (34)2 -2 = 1154
View AnswerQ5. |
| 1) | 3/2 | 2) | 31/2 |
| 3) | 127/108 | 4) | 121/108 |
| 5) | None of these | ||
Answer : 121/108
View AnswerQ6. |
| 1) | 0 | 2) | 1 |
| 3) | 2 | 4) | 3 |
| 5) | None of these | ||
Answer : 0
View AnswerQ7. | What is |
?| 1) | 2 | 2) | 3 |
| 3) | 4 | 4) | 5 |
| 5) | None of these | ||
Answer : 3
View AnswerQ8. |
| 1) | 3/7 | 2) | 1 |
| 3) | 2 | 4) | 4 |
| 5) | None of these | ||
Answer : 1
View AnswerQ9. |
| 1) | 7/8 | 2) | 5/8 |
| 3) | 2/3 | 4) | 1/6 |
| 5) | None of these | ||
Answer : 2/3
View AnswerQ10. |
| 1) | 20/169 | 2) | 1 |
| 3) | 5/4 | 4) | 3/4 |
| 5) | None of these | ||
Answer : 5/4
View Answer