Question

1. Mohan has marks of 92, 85, and 78 in three mathematics tests. In order to have an average of each
87 for the four math tests, he should obtain
(a) 93 marks (b) 90 marks (c) 92 marks
(0) 91 marks​

Answer 1

Answer:

93

Step-by-step explanation:

92 + 85 + 78 + x / 4 = 87

255 + x / 4 = 87

255 + x = 87 x 4

255 + x = 348

x = 348 - 255

x = 93

Answer 2

Answer:

The required marks = 93

Step-by-step explanation:

Given data

Marks of Mohan in 3 mathematics tests are 92, 85 and 78

⇒ here we need to find how much marks will he need in 4th mathematics test in order get 87 average marks  

⇒ Let x be the required marks  

⇒ average  of 4 tests marks will be   $\frac{92+85+78+x}{4} = 87$  

                                               ⇒     92+85+78+x = 348

                                               ⇒     255 + x = 348  

                                               ⇒        x = 93

the required marks = 93