If 893 × 78 = p, which of the following is equal to 893 × 79?

Question

(A) p + 1
(B) p + 78
(C) p + 79
(D) p + 893
(E) p + 894

Kudos for a correct  solution .

BrentGMATPrepNow · Accepted Answer

Given:  893 x 78 = P

893 x 79 = 893 x (78 + 1) 
=  (893)(78)  + (893)(1)
=  P  + 893
= D

Cheers,
Brent

kreel11 · Answer

No need to do all these steps if you are clear about the concept of multiplication you can straight away mark the answer within 10 seconds. We know that any constant number multiplied by increment of 1 actually adds the same constant to the previous result. For instance 4*2 = 8
4*3 = 12 which is 8 from previous result + constant 4 which is being multiplied everytime. Multiplication is repeated addition. Hence answer is p+893

Skywalker18 · Answer

893x79= 893x(78+1)
 = 893x 78 + 893x1
 = p+ 893
Answer D

ayushi219 · Answer

Given: 893 * 78 = p;

To Find: 893 * 79?

893 * 78 = p ---- Eq. 1
893 * 79 = 893 * (78+1) = 893*78 + 893*1 ---Eq. 2 Substituting Eq 1 in Eq 2 (893*78=p)
Hence, 
p+893

Answer D; p+893

MathRevolution · Answer

Forget conventional ways of solving math questions. In PS, IVY approach is the easiest and quickest way to find the answer.

If 893 × 78 = p, which of the following is equal to 893 × 79?

(A) p + 1
(B) p + 78
(C) p + 79
(D) p + 893
(E) p + 894

Since 893 × 78 = p and 79=78+1, we have 893 × 79 = 893 ×(78+1)=893×78 + 893 ×1 = p + 893.

The answer is (D).

Mun20 · Answer

893*78=p (given)
893*79 = 893*(78+1)
78=p/893
893*(p/893+1)
=p+893

kreel11 · Answer

No need to do all these steps if you are clear about the concept of multiplication you can straight away mark the answer within 10 seconds. We know that any constant number multiplied by increment of 1 actually adds the same constant to the previous result. For instance 4*2 = 8
4*3 = 12 which is 8 from previous result + constant 4 which is being multiplied everytime. Multiplication is repeated addition. Hence answer is p+893

FANewJersey · Answer

https://i.imgur.com/pQ72yJE.png

longhaul123 · Answer

I have a doubt in Option E 
So P+894= 893*78+894 = (893*78)+ (893+1)=893(78+1)=893*79
Im sure that there is some mistake with the method that i followed above but Im not understanding where am i going wrong because if you back solve from the above method 893(78+1)=893*78+893. Can someone help ?

BrentGMATPrepNow · Answer

There's a problem where you get  893(78+1)=893*79

You are correct to say that P+894= 893*78+894 = (893*78)+ (893+1)
However, the next step cannot be the one you took
You are treating (893+1) as though it were (893*1)

Notice that  if  we have (893*78)+ (893*1), then we can factor out the 893 to get: (893*78)+ (893*1) = 893(78 + 1)
However, If we have (893*78) + (893 + 1), we cannot factor out the 893 (as I did above)

Does that help?

Cheers,
Brent

ScottTargetTestPrep · Answer

We are given that 893 x 78 = p and need to determine, in terms of p, the value of 893 x 79.
 
893 x 79 can be expressed as: 893 x (1 + 78) = 893 + 893 x 78.
 
Since p = 893 x 78, we can substitute p for 893 x 78 in the expression 893 + 893 x 78.
 
Thus, 893 x 79 = 893 + p

Alternate Solution:

The multiplication 893 x 78 means that we add 893 a total of 78 times, and this sum is equal to p. Now if we perform the multiplication problem 893 x 79, it means that we will add one more 893 to the previous sum, so we have p + 893 as our answer.

Answer: D

KSBGC · Answer

what's the difference between 893 x 78 and 893 x 79.

In 893 x 79, 893 was counted once more.

It means , 893 x 78 + 893 = p + 893.

The best answer is D.

Kinshook · Answer

If 893 × 78 = p, which of the following is equal to 893 × 79?

893*78 = p
893*79 = 893*(78+1) = 893*78 + 893 = p + 893

IMO D

sahuanamika · Answer

No need of multiplying , this is a simple table concept:
For example in table of 5 :

5*2 = 10
5*3 = 15 i.e 10+5 , we add 5 each time to get the result.
Same concept can be applied here :
893 × 78 = p, 
893 × 79 = p+ 893 as this is the table of 893 we have increased the multiplier from 78 to 79 so simply adding 893 to the final result.

Option D

sushi600 · Answer

Is there a way of solving this question without having to recognize or memorize the table of 893?

rightday1121 · Answer

Very interesting question.

Given: 893 x 78 = P

893 x 79 = 893 x (78 + 1)

Using the distributive property:
= (893)(78) + (893)(1)
= P + 893  
= D

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If 893 × 78 = p, which of the following is equal to 893 × 79?

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If 893 × 78 = p, which of the following is equal to 893 × 79?

Prep Toolkit

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